Library to drive the Microchip 23K256 SRAM over SPI.
Dependencies:
mbed
main.cpp@0:318f4f480b1b, 2010-08-14 (annotated)
- Committer:
- romilly
- Date:
- Sat Aug 14 20:15:08 2010 +0000
- Revision:
- 0:318f4f480b1b
- Child:
- 1:28eb43851e6e
Who changed what in which revision?
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| romilly |
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#include "mbed.h"
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DigitalOut ncs(p14);
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SPI spi(p5,p6,p7);
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void on() {
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ncs = 0;
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}
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void off() {
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ncs = 1;
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}
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void write(int address, char byte) {
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on();
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spi.write(0x02); // write data
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spi.write(address >> 8);
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spi.write(address & 0xFF);
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spi.write(byte);
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off();
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}
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void write(int address, char * buffer, int count) {
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on();
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spi.write(0x01); // write status
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spi.write(0x40); // sequential mode
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off();
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on();
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spi.write(0x02);
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spi.write(address >> 8);
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spi.write(address & 0xFF);
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for (int i = 0; i < count; i++) {
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spi.write(buffer[i]);
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}
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off();
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on();
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spi.write(0x01); // write status
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spi.write(0x0); // byte mode
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off();
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}
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char read(int address) {
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on();
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spi.write(0x03);
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spi.write(address >> 8);
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spi.write(address & 0xFF);
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int result = spi.write(0);
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off();
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return (char) result;
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}
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int main() {
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off();
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char buff[50];
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write(0, 'h');
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write(1, 'i');
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write(2, '!');
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write(3, '\0');
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for (int address = 0; address < 4; address++) {
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buff[address] = read(address);
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}
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printf("mem = %s\r\n", buff);
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write(0, "Hello world!",12);
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for (int address = 0; address < 12; address++) {
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buff[address] = read(address);
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}
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buff[12]='\0';
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printf("now = %s\r\n", buff);
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} |
Romilly Cocking
Microchip 23K256 SRAM