SPI RAM 23LC1024 (Microchip) 1Mbit see: http://mbed.org/users/okini3939/notebook/extend-memory/

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
okini3939
Date:
Fri Nov 09 06:23:54 2012 +0000
Parent:
0:c5ba7d914282
Commit message:
fix

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
diff -r c5ba7d914282 -r a7b1803dfa44 main.cpp
--- a/main.cpp	Fri Nov 09 00:32:20 2012 +0000
+++ b/main.cpp	Fri Nov 09 06:23:54 2012 +0000
@@ -1,5 +1,6 @@
 /*
  * SPI RAM 23LC1024 (Microchip)
+ *   1Mbit
  */
 #include "mbed.h"
 
@@ -12,7 +13,7 @@
 Serial pc(USBTX, USBRX);
 
 SPI spi(p11, p12, p13); // mosi, miso, sclk
-DigitalOut cs(p17);
+DigitalOut cs(p17), hold(p18);
 
 int ram_write (int addr, char *buf, int len) {
     int i;
@@ -49,9 +50,12 @@
 int main() {
     int i;
     char buf[256];
+    Timer t;
 
     cs = 1;
+    hold = 1;
     pc.baud(115200);
+    spi.frequency(16000000);
     wait_ms(500);
     
     cs = 0;
@@ -59,6 +63,8 @@
     printf("RAM mode: %02x\r\n", spi.write(0));
     cs = 1;
     
+    printf("\r\nHELLO test\r\n");
+    
     printf("RAM write\r\n");
     strcpy(buf, "Hello!");
     ram_write(0, buf, 6);
@@ -68,7 +74,7 @@
     }
     ram_write(6, buf, 256);
 
-    wait_ms(500);
+    wait(1);
     memset(buf, 0, 256);
     
     printf("RAM read\r\n");
@@ -79,10 +85,35 @@
             printf("\r\n");
     }
 
-    while(1) {
-        myled = 1;
-        wait(0.2);
-        myled = 0;
-        wait(0.2);
+    wait(1);
+
+    printf("\r\nWrite/Read time\r\n");
+
+    printf("RAM write\r\n");
+    t.reset();
+    t.start();
+    for (i = 0; i < 0x20000; i += 256) {
+        buf[0] = (i >> 8) & 0xff;
+        ram_write(i, buf, 256);
+        if ((i & 0x0fff) == 0) printf(".");
     }
+    t.stop();
+    printf("\r\ntime %f, %f KBytes/sec\r\n", t.read(), (float)0x20000 / 1024 / t.read());
+
+    wait(1);
+
+    printf("RAM read\r\n");
+    t.reset();
+    t.start();
+    for (i = 0; i < 0x20000; i += 256) {
+        ram_read(i, buf, 256);
+        if (buf[0] != ((i >> 8) & 0xff)) {
+            printf("error %d\r\n", i);
+            break;
+        }
+        if ((i & 0x0fff) == 0) printf(".");
+    }
+    t.stop();
+    printf("\r\ntime %f, %f KBytes/sec\r\n", t.read(), 0x20000 / 1024 / t.read());
+
 }