1 files changed, 122 insertions, 0 deletions
diff --git a/examples/test-fsmc.cpp b/examples/test-fsmc.cpp
new file mode 100644
index 0000000..1621317
--- /dev/null
+++ b/examples/test-fsmc.cpp
@@ -0,0 +1,122 @@
+#include <stddef.h>             // for ptrdiff_t
+
+#include <wirish/wirish.h>
+#include <libmaple/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);
+
+    SerialUSB.read();
+    SerialUSB.println("*** Beginning RAM chip test");
+
+    test_single_write();
+    test_all_addresses();
+
+    SerialUSB.println("Tests pass, finished.");
+    SerialUSB.println("***\n");
+}
+
+void loop() {
+}
+
+void test_single_write() {
+    uint16 *ptr = sram_start;
+    uint16 tmp;
+
+    SerialUSB.print("Writing 0x1234... ");
+    *ptr = 0x1234;
+    SerialUSB.println("Done.");
+
+    SerialUSB.print("Reading... ");
+    tmp = *ptr;
+    SerialUSB.print("Done: 0x");
+    SerialUSB.println(tmp, HEX);
+
+    if (tmp != 0x1234) {
+        SerialUSB.println("Mismatch; abort.");
+        ASSERT(0);
+    }
+}
+
+void test_all_addresses() {
+    uint32 start, end;
+    uint16 count = 0;
+    uint16 *ptr;
+
+    SerialUSB.println("Now writing all memory addresses (unrolled loop)");
+    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.print("Done. Elapsed time (us): ");
+    SerialUSB.println(end - start);
+
+    SerialUSB.println("Validating writes.");
+    for (ptr = sram_start, count = 0; ptr < sram_end; ptr++, count++) {
+        uint16 value = *ptr;
+        if (value != count) {
+            SerialUSB.print("mismatch: 0x");
+            SerialUSB.print((uint32)ptr);
+            SerialUSB.print(" = 0x");
+            SerialUSB.print(value, HEX);
+            SerialUSB.print(", should be 0x");
+            SerialUSB.print(count, HEX);
+            SerialUSB.println(".");
+            ASSERT(0);
+        }
+    }
+    SerialUSB.println("Done; all writes seem valid.");
+
+    ptrdiff_t nwrites = sram_end - sram_start;
+    double us_per_write = double(end-start) / double(nwrites);
+    SerialUSB.print("Number of writes = ");
+    SerialUSB.print(nwrites);
+    SerialUSB.print("; avg. time per write = ");
+    SerialUSB.print(us_per_write);
+    SerialUSB.print(" us (");
+    SerialUSB.print(1 / us_per_write);
+    SerialUSB.println(" MHz)");
+}
+
+__attribute__((constructor)) void premain() {
+    init();
+}
+
+int main(void) {
+    setup();
+
+    while (true) {
+        loop();
+    }
+
+    return 0;
+}