Serial Output Error

beardcm · 2005-04-08 20:08

When running RealTerm, the output·of the code produces strings of decimal numbers of the correct length.· However, the output strings to not match·the string of decimal numbers specified inside the code for a given word.·

What could be causing this to·happen?

Beau Schwabe · 2005-04-08 20:13

Is it inverted?

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Beau Schwabe - Mask Designer III

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beardcm · 2005-04-08 20:17

The strings stored in the string memory locations are exactly what we need to be sent out of the chip. There seems to be no correlation between the output inverted (using realTerm inverted viewing) or otherwise.

Beau Schwabe · 2005-04-08 20:22

I'm not sure about the "realTerm inverted viewing".... what I meant was are you transmitting the data from the SX as "inverted" or "non-inverted".

You asked what could be causing this to happen. This was the first thing that I thought of that might be a culprit.

A quick look at "realTerm" and the option to invert the data is NOT the same as inverting the RS232 serial data leaving the SX / entering the PC

realterm.sourceforge.net/

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Beau Schwabe - Mask Designer III

National Semiconductor Corporation
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Post Edited (Beau Schwabe) : 4/8/2005 8:30:12 PM GMT

beardcm · 2005-04-08 20:40

In the sendbyte subroutine, I have tried removing the not w command and while the output it gives is different, but it is still not the same as the numerical values stored in the string. With or without the inverted setting in realterm. I thought maybe it was an issue of timing, due to the fact there are two different baud rates involved in the programming. Trying various values for intperiod variable alters the output, yet it still isn't the output we are looking for, which is why I was wondering if there might be something else about the program that may be causing the problem.

Beau Schwabe · 2005-04-08 20:56

The "not w command" only inverts the data.....

Ok... A serial BYTE is actually 10-bits. You have 8-Data bits that compose a Byte, and you have a START and a STOP bit
that make up the other 2-bits totaling 10-bits.

The inversion that I am suggesting is in the "BaudMode" setting as part of the SEROUT routine. When this is set, not only are the DATA
bits inverted (same as the 'not w command' or flipping this in the realTerm) BUT, the STOP and START bits are also inverted.

Now, you mention that you have different baud speeds. This needs to be corrected first! you should have the same Baud setting for
everything within the SX and within realTerm.

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Beau Schwabe - Mask Designer III

National Semiconductor Corporation
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beardcm · 2005-04-08 22:00

As to the problem of the baud rates being different, the two devices that I need to connect together run at two different baud rates. If it were up to me I would not be attempting to do this, but as this is my senior project and the parts were recommended by the sponsors, I am kind of stuck.

Beau Schwabe · 2005-04-08 22:09

What about using a different pin for the different bauds? ....At least for debugging?
I still think you are going to have problems mixing different baud modes.
It is important to work out a common denominator that you can transmit and receive data with.

Also, I assume you are programming on an SX.. Are you using SX/Basic or SX/Assembly for your programming?

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Beau Schwabe - Mask Designer III

National Semiconductor Corporation
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(Communication Interface Division)
500 Pinnacle Court, Suite 525
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beardcm · 2005-04-10 00:54

I am using assembly language.

Jim Palmer · 2005-04-11 16:57

What was the output for the welcome string you are sending when you generate it with the program you attached to your original message?

Jim

beardcm · 2005-04-11 22:03

I figured out what the problem with the output speed, it was probably a typo in the original program.
But, now we get extra numbers before the output that is supposed to correspond to the values for welcome.

Intended output: 84,147,131,145,195,136,140,255,0
Actual output: 0 140 140 112 124 31 0 12 28 31 56 130 168 77 131 145 195 136 140 255

Here is the new code, with the problem fixed.

LIST Q = 37 ;disables truncation errors

device SX28,oschs2,turbo,stackx,optionx

freq 50_000_000

IRC_CAL IRC_FAST

; ** Baud Rates for UART 1 **
U1B1200 ;baud rate of 1.2 Kbps

; ** Baud Rates for UART 2 **
U2B9600 ;baud rate of 9.6 kbps

id '2UART VP' ;
reset resetEntry ; set reset vector

;*********************************************************************************************
;

Macro's

; Macro: _bank
; Sets the bank appropriately for all revisions of SX.
;
; This is required since the bank instruction has only a 3-bit operand, it cannot be used to
; access all 16 banks of the SX48/52. FSR.7 (SX48/52bd production release) needs to be set
; appropriately, depending on the bank address being accessed. This macro fixes this.
;
; So, instead of using the bank instruction to switch between banks, use _bank instead.
;*********************************************************************************************

_bank macro 1
noexpand
bank \1

expand
clrb fsr.7
noexpand

endm

;*********************************************************************************************
; Macro: _mode
; Sets the MODE register appropriately for all revisions of SX.
;
; This is required since the MODE (or MOV M,#) instruction has only a 4-bit operand.
; The SX28AC use only 4 bits of the MODE register, however the SX48/52BD have
; the added ability of reading or writing some of the MODE registers, and therefore use
; 5-bits of the MODE register. The MOV M,W instruction modifies all 8-bits of the
; MODE register, so this instruction must be used on the SX48/52BD to make sure the MODE
; register is written with the correct value. This macro fixes this.
;
; So, instead of using the MODE or MOV M,# instructions to load the M register, use
; _mode instead.
;*********************************************************************************************

_mode macro 1

noexpand

expand
mov m,#\1 ;loads the M register correctly for the SX18AC, SX20AC
;and SX28AC
noexpand

endm

;*********************************************************************************************
; INCP/DECP macros for incrementing/decrementing pointers to RAM
; used to compensate for incompatibilities between SX28AC and SX52BD
;*********************************************************************************************

INCP macro 1 ; Increments a pointer to RAM

setb \1.4 ; If SX18 or SX28AC,keep bit 4 of the pointer = 1
; to jump from $1f to $30,etc
endm

DECP macro 1 ; Decrements a pointer to RAM

clrb \1.4 ; If SX18 or SX28AC, forces rollover to next bank
dec \1 ; if it rolls over. (skips banks with bit 4 = 0)
setb \1.4 ; Eg: $30 ---> $20 ---> $1f ---> $1f
; AND: $31 ---> $21 ---> $20 ---> $30
endm

;*********************************************************************************************
; Error generating macros
; Used to generate an error message if the label is intentionally moved into the second page.
; Use for lookup tables.
;*********************************************************************************************

tablestart macro 0 ; Generates an error message if code that MUST be in
; the first half of a page is moved into the second half
if $ & $100
ERROR 'Must be located in the first half of a page.'
endif
endm

tableEnd macro 0 ; Generates an error message if code that MUST be in
; the first half of a page is moved into the second half

if $ & $100
ERROR 'Must be located in the first half of a page.'
endif
endm

;*********************************************************************************************
;

Memory Organization

;*********************************************************************************************

;*********************************************************************************************
;

Data Memory address definitions

; These definitions ensure the proper address is used for banks 0 - 7 for 2K SX devices
; (SX28) and 4K SX devices (SX48/52).
;*********************************************************************************************

global_org = $08
bank0_org = $10
bank1_org = $30
bank2_org = $50
bank3_org = $70
bank4_org = $90
bank5_org = $B0
bank6_org = $D0
bank7_org = $F0

;*********************************************************************************************
;

Global Register definitions

; NOTE: Global data memory starts at $0A on SX48/52 and $08 on SX18/20/28.
;*********************************************************************************************

org global_org

flags0 equ global_org + 0 ; stores bit-wise operators like flags
; and function-enabling bits (semaphores)
;

VP: RS232 Receive

rs232Tx1Flag equ flags0.0 ;indicates that UART1 is transmitting if set or not transmitting if reset
rs232Tx2Flag equ flags0.1 ;indicates that UART2 is transmitting if set or not transmitting if reset
rs232Rx1Flag equ flags0.2 ;indicates that UART1 has received a byte if set
rs232Rx2Flag equ flags0.3 ;indicates that UART2 has received a byte if set

isrTemp0 equ global_org + 1 ; Interrupt Service Routine's temp register.
; Don't use this register in the mainline.

localTemp0 equ global_org + 2 ; temporary storage register
; Used by first level of nesting
; Never guaranteed to maintain data

localTemp1 equ global_org + 3 ; temporary storage register
; Used by second level of nesting
; or when a routine needs more than one
; temporary global register.

localTemp2 equ global_org + 4 ; temporary storage register
; Used by third level of nesting or by
; main loop routines that need a loop
; counter, etc.

;*********************************************************************************************
;

RAM Bank Register definitions

;*********************************************************************************************

;*********************************************************************************
; Bank 0
;*********************************************************************************

org bank0_org

bank0 = $

;*********************************************************************************
; Bank 1
;*********************************************************************************

org bank1_org

bank1 = $
rs232TxBank = $ ;UART Transmit bank
rs232Tx1High ds 1 ;High Byte to be transmitted
rs232Tx1Low ds 1 ;Low Byte to be transmitted
rs232Tx1Count ds 1 ;counter to keep track of the bits sent
rs232Tx1Divide ds 1 ;xmit timing counter
rs232Tx1Byte ds 1 ;store the byte to be sent in this buffer

rs232Tx2High ds 1 ;High Byte to be transmitted
rs232Tx2Low ds 1 ;Low Byte to be transmitted
rs232Tx2Count ds 1 ;counter to keep track of the bits sent
rs232Tx2Divide ds 1 ;xmit timing counter
rs232Tx2Byte ds 1 ;store the byte to be sent in this buffer

MultiplexBank = $ ;Multipler Bank
isrMultiplex ds 1 ;Used to jump between the ISR Threads when
; an Interrupt occurs

;*********************************************************************************
; Bank 2
;*********************************************************************************

org bank2_org

bank2 = $
rs232RxBank = $

rs232Rx1Count ds 1 ;counter to keep track of the number of bits received
rs232Rx1Divide ds 1 ;receive timing counter
rs232Rx1Byte ds 1 ;buffer for incoming byte
rs232Byte1 ds 1 ;Used by serial routines

rs232Rx2Count ds 1 ;counter to keep track of the number of bits received
rs232Rx2Divide ds 1 ;receive timing counter
rs232Rx2Byte ds 1 ;buffer for incoming byte
rs232Byte2 ds 1 ;used by serial routines

;*********************************************************************************
; Bank 3
;*********************************************************************************

org bank3_org

bank3 = $

;*********************************************************************************
; Bank 4
;*********************************************************************************

org bank4_org

bank4 = $

;*********************************************************************************
; Bank 5
;*********************************************************************************

org bank5_org

bank5 = $

;*********************************************************************************
; Bank 6
;*********************************************************************************

org bank6_org

bank6 = $

;*********************************************************************************
; Bank 7
;*********************************************************************************

org bank7_org

bank7 = $

;*****************************************************************************************
;

Port Assignment

;*****************************************************************************************

RA_latch equ %00000000 ;SX28/48/52 port A latch init ;intial value after reset
RA_DDIR equ %11111111 ;SX28/48/52 port A DDIR value ;0=Output,1=Input
RA_LVL equ %00000000 ;SX28/48/52 port A LVL value ;0=CMOS,1=TTL
RA_PLP equ %00000000 ;SX28/48/52 port A PLP value ;0=Enable,1=Disable

RB_latch equ %10001000 ;SX28/48/52 port B latch init ;intial value after reset
RB_DDIR equ %01110111 ;SX28/48/52 port B DDIR value ;0=Output,1=Input
RB_ST equ %11111111 ;SX28/48/52 port B ST value ;0=Enable,1=Disable
RB_LVL equ %00000000 ;SX28/48/52 port B LVL value ;0=CMOS,1=TTL
RB_PLP equ %11001100 ;SX28/48/52 port B PLP value ;0=Enable,1=Disable

RC_latch equ %00000000 ;SX28/48/52 port C latch init ;intial value after reset
RC_DDIR equ %11111111 ;SX28/48/52 port C DDIR value ;0=Output,1=Input
RC_ST equ %11111111 ;SX28/48/52 port C ST value ;0=Enable,1=Disable
RC_LVL equ %00000000 ;SX28/48/52 port C LVL value ;0=CMOS,1=TTL
RC_PLP equ %00000000 ;SX28/48/52 port C PLP value ;0=Enable,1=Disable

;*********************************************************************************************
;

Pin Definitions

;*********************************************************************************************

rs232Rxpin1 equ rb.6 ;UART1 receive input
rs232Txpin1 equ rb.7 ;UART1 transmit output

rs232Rxpin2 equ rb.2 ;UART2 receive input
rs232Txpin2 equ rb.3 ;UART2 transmit output

;*********************************************************************************************
;

Program constants

;*********************************************************************************************

;*********************************************************************************************
; UART Constants values
;*********************************************************************************************

intPeriod = -217
UARTfs = 230400

Num = 4 ; Number of times ISR thread1 is called in the
; ISRMultiplexer
IFDEF U1B1200
UARTBaud1 = 1200

UARTDivide1 = (UARTfs/(UARTBaud1*Num)) ;48
UARTStDelay1 = UARTDivide1 +(UARTDivide1/2)+1

IFDEF U2B9600
UARTBaud2 = 9600

UARTDivide2 = (UARTfs/(UARTBaud2*Num)) ;6
UARTStDelay2 = UARTDivide2 +(UARTDivide2/2)+1

;*********************************************************************************************
; SX28AC Mode addresses
; *On SX28, all registers addressed via mode are write only, with the exception of
; CMP and WKPND which do an exchange with W.
;*********************************************************************************************

;

Exchange addresses

CMP equ $08 ;Exchange Comparator enable/status register with W
WKPND equ $09 ;Exchange MIWU/RB Interrupts pending with W

;

Port setup (read) addresses

WKED_W equ $0A ;Write MIWU/RB Interrupt edge setup, 1 = falling, 0 = rising
WKEN_W equ $0B ;Write MIWU/RB Interrupt edge setup, 0 = enabled, 1 = disabled
ST_W equ $0C ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled
LVL_W equ $0D ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled
PLP_W equ $0E ;Write Port Schmitt Trigger setup, 0 = enabled, 1 = disabled
DDIR_W equ $0F ;Write Port Direction

ENDIF

;*********************************************************************************************
;

Program memory ORG defines

;*********************************************************************************************

INTERRUPT_ORG equ $0 ; Interrupt must always start at location zero
RESETENTRY_ORG equ $1FB ; The program will jump here on reset
SUBROUTINES_ORG equ $200 ; The subroutines are in this location
STRINGS_ORG equ $300 ; The strings are in the location $300
PAGE3_ORG equ $400 ; Page 3 is empty
MAINPROGRAM_ORG equ $600 ; The main program is in the lastpage of program memory

;*********************************************************************************************
org INTERRUPT_ORG ; First location in program memory.
;*********************************************************************************************

;*********************************************************************************************
;

Interrupt Service Routine

; Note 1: The interrupt code must always originate at address $0.
; Interrupt Frequency = (Cycle Frequency / -(retiw value))
; For example: With a retiw value of -217 and an oscillator frequency
; of 50MHz, this code runs every 4.32us.
; Note 2: Mode Register 'M' is not saved in SX 28 but saved in SX 52 when an Interrupt
; occurs. If the code is to run on a SX 28 and 'M' register is used in the ISR,
; then the 'M' register has to be saved at the Start of ISR and restored at the
; End of ISR.
;*********************************************************************************************
org $0
interrupt ;3

;*********************************************************************************************
; Interrupt
; Interrupt Frequency = (Cycle Frequency / -(retiw value)) For example:
; With a retiw value of -217 and an oscillator frequency of 50MHz, this code runs
; every 4.32us.
;*********************************************************************************************

;*********************************************************************************************
;

VP:VP Multitasker

; Virtual Peripheral Multitasker : up to 16 individual threads, each running at the
; (interrupt rate/16). Change them below:
;Input variable(s): isrmultiplex: variable used to choose threads
;Output variable(s): None,executes the next thread
;Variable(s) affected: isrmultiplex
;Flag(s) affected: None
;Program Cycles: 9 cycles (turbo mode)
;*********************************************************************************************

_bank Multiplexbank ;
inc isrMultiplex ; toggle interrupt rate
mov w,isrMultiplex ;

;*********************************************************************************************
; The code between the tableStart and tableEnd statements MUST be completely within the first
; half of a page. The routines it is jumping to must be in the same page as this table.
;*********************************************************************************************

tableStart ; Start all tables with this macro
jmp pc+w ;
jmp isrThread1 ;
jmp isrThread2 ;
jmp isrThread3 ;
jmp isrThread4 ;
jmp isrThread1 ;
jmp isrThread5 ;
jmp isrThread6 ;
jmp isrThread7 ;
jmp isrThread1 ;
jmp isrThread8 ;
jmp isrThread9 ;
jmp isrThread10 ;
jmp isrThread1 ;
jmp isrThread11 ;
jmp isrThread12 ;
jmp isrThread13 ;
tableEnd ; End all tables with this macro.

;*********************************************************************************************
;VP: VP Multitasker
; ISR TASKS
;*********************************************************************************************

isrThread1 ; Serviced at ISR rate/4

;*********************************************************************************************
; Virtual Peripheral: Universal Asynchronous Receiver Transmitter (UART) These routines send
; and receive RS232 serial data, and are currently configured (though modifications can be
; made) for the popular "No parity-checking, 8 data bit, 1 stop bit" (N,8,1) data format.
;
; The VP below has 2 UARTS implemented - UART1 & UART2. Both the UARTs can work at independent
; Baud Rates.
;
; RECEIVING: The rs232Rx1flag & rs232Rx2flag are set high whenever a valid byte of data has
; been received and it is the calling routine's responsibility to reset this flag once the
; incoming data has been collected.
;
; TRANSMITTING: The transmit routine requires the data to be inverted and loaded
; (rs232Txhigh+rs232Txlow) register pair (with the inverted 8 data bits stored in
; rs232Txhigh and rs232Txlow bit 7 set high to act as a start bit). Then the number of bits
; ready for transmission (10=1 start + 8 data + 1 stop) must be loaded into the rs232Txcount
; register. As soon as this latter is done, the transmit routine immediately begins sending
; the data. This routine has a varying execution rate and therefore should always be
; placed after any timing-critical virtual peripherals such as timers,
; adcs, pwms, etc.
; Note: The transmit and receive routines are independent and either may be removed for each
; of the UARTs. The initial "_bank rs232TxBank" & "_bank rs232RxBank" (common)
; instruction is kept for Transmit & Receive routines.
; Input variable(s) : rs232Tx1Low (only high bit used), rs232Tx1High, rs232Tx1Count
; If rs232Tx1Flag SET, then transmit on UART1
; rs232Tx2Low (only high bit used), rs232Tx2High, rs232Tx2Count
; If rs232Tx2Flag SET, then transmit on UART2
; Output variable(s) : rs232Rx1Flag, rs232Rx1Byte
; rs232Rx2Flag, rs232Rx2Byte
; Variable(s) affected : rs232Tx1Divide, rs232Rx1Divide, rs232Rx1Count
; rs232Tx2Divide, rs232Rx2Divide, rs232Rx2Count
; Flag(s) affected : rs232Tx1Flag, rs232Tx2Flag
; rs232Rx1Flag, rs232Rx1Flag
; Program cycles: 22 worst case for Tx, 23 worst case for Rx
; Variable Length? Yes.
;*********************************************************************************************
UART1
rs232Transmit
_bank rs232TxBank ;2 switch to serial register bank

sb rs232Tx1FLag ;1
jmp rs232Receive1 ;1
decsz rs232Tx1Divide ;1 only execute the transmit routine
jmp rs232Receive1 ;1
mov w,#UARTDivide1 ;1 load UART1 baud rate (50MHz)
mov rs232Tx1Divide,w ;1
test rs232Tx1Count ;1 are we sending?
snz ;1
jmp rs232Receive1 ;1

:txbit clc ;1 yes, ready stop bit
rr rs232Tx1High ;1 and shift to next bit
rr rs232Tx1Low ;1
dec rs232Tx1Count ;1 decrement bit counter
snb rs232Tx1Low.6 ;1 output next bit
clrb rs232TxPin1 ;1
sb rs232Tx1Low.6 ;1
setb rs232TxPin1 ;1
test rs232Tx1Count ;1 are we sending?
snz ;1
clrb rs232Tx1Flag ;1,22

rs232Receive1
_bank rs232RxBank ;2
sb rs232RxPin1 ;1 get current rx bit
clc ;1
snb rs232RxPin1 ;1
stc ;1
test rs232Rx1Count ;1 currently receiving byte?
sz ;1
jmp :rxbit ;1 if so, jump ahead
mov w,#9 ;1 in case start, ready 9 bits

mov rs232Rx1Count,w ;1 it is, so renew bit count
mov w,#UARTStDelay1 ;1 ready 1.5 bit periods (50MHz)
mov rs232Rx1Divide,w ;1
:rxbit decsz rs232Rx1Divide ;1 middle of next bit?
jmp :rs232RxOut1 ;1
mov w,#UARTDivide1 ;1 yes, ready 1 bit period (50MHz)
mov rs232Rx1Divide,w ;1
dec rs232Rx1Count ;1 last bit?
sz ;1 if not
rr rs232Rx1Byte ;1 then save bit
snz ;1 if so,
setb rs232Rx1Flag ;1,23 then set flag
:rs232RxOut1

UART2
_bank rs232TxBank ;2 switch to serial register bank
sb rs232Tx2flag ;1
jmp rs232Receive2 ;1
decsz rs232Tx2Divide ;1 only execute the transmit routine
jmp rs232Receive2 ;1
mov w,#UARTDivide2 ;1 load UART2 baud rate (50MHz)
mov rs232Tx2Divide,w ;1
test rs232Tx2Count ;1 are we sending?
snz ;1
jmp rs232Receive2 ;1

:txbit stc ;1 yes, ready stop bit
rr rs232Tx2High ;1 and shift to next bit
rr rs232Tx2Low ;1
dec rs232Tx2Count ;1 decrement bit counter
snb rs232Tx2Low.6 ;1 output next bit
clrb rs232TxPin2 ;1
sb rs232Tx2Low.6 ;1
setb rs232TxPin2 ;1
test rs232Tx2Count ;1 are we sending?
snz ;1
clrb rs232Tx2Flag ;1,22

rs232Receive2
_bank rs232RxBank ;2
sb rs232RxPin2 ;1 get current rx bit
clc ;1
snb rs232RxPin2 ;1
stc ;1
test rs232Rx2Count ;1 currently receiving byte?
sz ;1
jmp :rxbit ;1 if so, jump ahead
mov w,#9 ;1 in case start, ready 9 bits
sc ;1 skip ahead if not start bit
mov rs232Rx2Count,w ;1 it is, so renew bit count
mov w,#UARTStDelay2 ;1 ready 1.5 bit periods (50MHz)
mov rs232Rx2Divide,w ;1
:rxbit decsz rs232Rx2Divide ;1 middle of next bit?
jmp :rs232RxOut2 ;1
mov w,#UARTDivide2 ;1 yes, ready 1 bit period (50MHz)
mov rs232Rx2Divide,w ;1
dec rs232Rx2Count ;1 last bit?
sz ;1 if not
rr rs232Rx2Byte ;1 then save bit
snz ;1 if so,
setb rs232Rx2Flag ;1,23 then set flag
:rs232RxOut2

UARTOut

;*********************************************************************************************
;===================================== PUT YOUR OWN VPs HERE==================================
; Virtual Peripheral:
;
; Input variable(s):
; Output variable(s):
; Variable(s) affected:
; Flag(s) affected:
;*********************************************************************************************
;