New to the SX chip and forum. Have a couple of Beginner questions
Steel
Posts: 313
Hey, everyone...I am stepping over from the Stamp to the SX Chip and have a few assumptions that I need some yes/no 's on.· If you could help me out, that would be great...
1.· Board layout for running the chip:
···· The only required connections are
······· VSS(2) to Ground
······ ·VDD(2) to 5V (or 3.3, but easier to do 5V for programming)
······· MCLR to 5V with resistor, or to a switch/button for reset
2.· Board layout for programming the chip:
···· The only required connections are
······· VSS(2) to Ground
······ ·VDD(2) to 5V (or 3.3, but easier to do 5V for programming)
······· MCLR to 5V with resistor, or to a switch/button for reset
······· OSC1 to a OSC1 Pin for programmer
······· OSC2 to a OSC2 Pin for programmer
3.· There is no EEPROM or Resonator requirement (PROGRAM EEPROM is internal, Resonator up to 4MHz is· \internal)
4.· If you have an external crystal and are in programming mode, you must have a hardware 'disconnect' for your crystal from 'colliding' with the Programming oscillator.
5.· Port B can be used for Interrupt Inputs.
6.· Unless you have a Real Time Clock running, RTCC should be nc.
As you can guess, I am stepping over into the Assembly Language realm (I learned it on a Motorola Processor - 68HC11...but haven't used it at all), and I think this is a cost-effective means of running from the STAMP to lower-level programming.
Thank you for providing this chip, and having these forums available for customers.· There are very few manufacturers/distributors that provide this type of support.
Thanks for the help.
·······
1.· Board layout for running the chip:
···· The only required connections are
······· VSS(2) to Ground
······ ·VDD(2) to 5V (or 3.3, but easier to do 5V for programming)
······· MCLR to 5V with resistor, or to a switch/button for reset
2.· Board layout for programming the chip:
···· The only required connections are
······· VSS(2) to Ground
······ ·VDD(2) to 5V (or 3.3, but easier to do 5V for programming)
······· MCLR to 5V with resistor, or to a switch/button for reset
······· OSC1 to a OSC1 Pin for programmer
······· OSC2 to a OSC2 Pin for programmer
3.· There is no EEPROM or Resonator requirement (PROGRAM EEPROM is internal, Resonator up to 4MHz is· \internal)
4.· If you have an external crystal and are in programming mode, you must have a hardware 'disconnect' for your crystal from 'colliding' with the Programming oscillator.
5.· Port B can be used for Interrupt Inputs.
6.· Unless you have a Real Time Clock running, RTCC should be nc.
As you can guess, I am stepping over into the Assembly Language realm (I learned it on a Motorola Processor - 68HC11...but haven't used it at all), and I think this is a cost-effective means of running from the STAMP to lower-level programming.
Thank you for providing this chip, and having these forums available for customers.· There are very few manufacturers/distributors that provide this type of support.
Thanks for the help.
·······
Comments
Under "board layout for programming the chip" you should add pinouts for Vss and Vdd.
The SX key or SX blitz plug into a 4 pin header with OSC1, OSC2, Vss, and Vdd.
Vdd had to be 5V before, but I think there is an adapter available now that will let you program 3V projects.
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I wonder if this wire is hot...
Typical use of the RTCC has it driven by the internal clock, so even when it's running, there is no physical connection to it.
The internal oscillator should not be used for programs involving time critical communications (such as serial, Ir, etc).
Thanks, PeterM
it's a good habit, not to leave any inputs open and floating. As the RTCC input is rarely used, connect it to Vdd via a pull-up resistor (4.7 to 10 kOhm is fine). The same is true for any un-used I/O port pins. You may either configure them as outputs, or as inputs with the internal pull-up resistors activated.
Always place a bypass capacitor (100 nF, ceramic) between Vdd and Vss as close as possible to the chip's supply pins in order to reduce EMI. Also make sure that the traces for the OSC1 and OSC2 signals are as short as possible.
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Greetings from Germany,
G