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#include <stddef.h> // for ptrdiff_t
#include "wirish.h"
#include "fsmc.h"
#ifndef BOARD_maple_native
#error "Sorry, this example only works on Maple Native."
#endif
// Start of FSMC SRAM bank 1
static uint16 *const sram_start = (uint16*)0x60000000;
// End of Maple Native SRAM chip address space (512K 16-bit words)
static uint16 *const sram_end = (uint16*)0x60100000;
void test_single_write(void);
void test_all_addresses(void);
void setup() {
pinMode(BOARD_LED_PIN, OUTPUT);
digitalWrite(BOARD_LED_PIN, HIGH);
Serial1.begin(115200);
Serial1.println("*** Beginning RAM chip test");
test_single_write();
test_all_addresses();
Serial1.println("Tests pass, finished.");
Serial1.println("***\n");
}
void loop() {
}
void test_single_write() {
uint16 *ptr = sram_start;
uint16 tmp;
Serial1.print("Writing 0x1234... ");
*ptr = 0x1234;
Serial1.println("Done.");
Serial1.print("Reading... ");
tmp = *ptr;
Serial1.print("Done: 0x");
Serial1.println(tmp, HEX);
if (tmp != 0x1234) {
Serial1.println("Mismatch; abort.");
ASSERT(0);
}
}
void test_all_addresses() {
uint32 start, end;
uint16 count = 0;
uint16 *ptr;
Serial1.println("Now writing all memory addresses (unrolled loop)");
// Turn off the USB interrupt, as it interferes most with timing
// (don't turn off SysTick, or we won't get micros()).
SerialUSB.end();
start = micros();
for (ptr = sram_start; ptr < sram_end;) {
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
*ptr++ = count++;
}
end = micros();
SerialUSB.begin();
Serial1.print("Done. Elapsed time (us): ");
Serial1.println(end - start);
Serial1.println("Validating writes.");
for (ptr = sram_start, count = 0; ptr < sram_end; ptr++, count++) {
uint16 value = *ptr;
if (value != count) {
Serial1.print("mismatch: 0x");
Serial1.print((uint32)ptr);
Serial1.print(" = 0x");
Serial1.print(value, HEX);
Serial1.print(", should be 0x");
Serial1.print(count, HEX);
Serial1.println(".");
ASSERT(0);
}
}
Serial1.println("Done; all writes seem valid.");
ptrdiff_t nwrites = sram_end - sram_start;
double us_per_write = double(end-start) / double(nwrites);
Serial1.print("Number of writes = ");
Serial1.print(nwrites);
Serial1.print("; avg. time per write = ");
Serial1.print(us_per_write);
Serial1.print(" us (");
Serial1.print(1 / us_per_write);
Serial1.println(" MHz)");
}
__attribute__((constructor)) void premain() {
init();
}
int main(void) {
setup();
while (true) {
loop();
}
return 0;
}
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