Is there a better or simpler way to do this?
Don M
Posts: 1,652
This code looks at some serial data being received. There are 3 bytes- 2 data and 1 checksum.
The data is received in and the checksum verified before the message is displayed.
This code works but looks rather long. Seems like a lot of redundency. Was wondering if there is a simpler way.
Thanks.
Don
The data is received in and the checksum verified before the message is displayed.
This code works but looks rather long. Seems like a lot of redundency. Was wondering if there is a simpler way.
repeat
s := serial.rx_time(10)
case s
$01: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 1", 13))
quit
quit
$02: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 2", 13))
quit
quit
$03: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 3", 13))
quit
quit
$04: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 4", 13))
quit
quit
$05: checksum += s
s := serial.rx_time(2)
case s
$10: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 5", 13))
quit
quit
$20: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 6", 13))
quit
quit
quit
$06: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 7", 13))
quit
quit
$11: checksum += s
s := serial.rx_time(2)
case s
$00: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 8", 13))
quit
quit
$10: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 9", 13))
quit
quit
$11: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 10", 13))
quit
quit
$30: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 11", 13))
quit
quit
$41: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 12", 13))
quit
quit
$50: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 13", 13))
quit
quit
$51: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 14", 13))
quit
quit
$52: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 15", 13))
quit
quit
$53: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 16", 13))
quit
quit
$54: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 17", 13))
quit
quit
quit
$15: checksum += s
s := serial.rx_time(2)
case s
$00: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 18", 13))
quit
quit
$02: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 19", 13))
quit
quit
$03: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 20", 13))
quit
quit
$04: repeat until (s & $F_00) == $1_00
checksum += s
s := serial.rx_time(2)
if (s & $0_FF) == checksum
ch_seq++
term.str(string("Message 21", 13))
quit
quit
quit
Thanks.
Don
Comments
If it fits, and the space is not wanted for anything else, then it is fine as it is...
(sometimes, expanded code is the fastest..)
As for general clarity, some tools allow macros, or In-line expansion, so you get the same binary, but oft repeated Text can be written once.
Not sure about Spin ? (a pre-processor could do this for you ? )
Or, you can re-code what you have, to move as much common stuff outside the individual CASEs to a common area.
Sometimes, that may need an 'undo' line added in infrequent not-needed cases.
Overall size is smaller, but it may not be faster.
I think the more important question is how will this code behave if you really have transmission problems! Will it recover? I don't think that it will recover by intention, more by chance! The mentioned code improvements won't change anything on recovery-behaviour.
You should give us more details about the protocol, so that we can give better advice also in regards to recovery.
In general optimizing code means to find similarities and make functions out of the similar parts using parameters in the parts that are embedded in similar code but are actually different. For example in the outer case statement cases from $01-$04 everything is exactly the same except the message number. So you can make it a function which accepts the message number as a parameter.
repeat s := serial.rx_time(10) case s $01..$04,$06: tmp := s repeat until (s & $F_00) == $1_00 checksum += s s := serial.rx_time(2) if (s & $0_FF) == checksum ch_seq++ term.str(string("Message ")) term.dec(s) term.tx(13) quit quit $05: checksum += s s := se'...Or you could break the REPEAT UNTIL... into a method/function.