Diff: main.cpp

Revision:

5:c79a6e66ed00

Parent:

4:241cd0193031

Child:

6:dccae7a269f9

--- a/main.cpp	Wed Nov 19 06:26:09 2014 +0000
+++ b/main.cpp	Mon Sep 07 05:31:33 2015 +0000
@@ -1,3 +1,4 @@
+/* Implement the SPI slave 8-bit in hardware */
 #include "mbed.h"
 
 //#include <stdarg.h>
@@ -5,6 +6,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <SPISlave.h>
+
 /*
 Instructions for use: connect the mbed to a parallel port using these connexions.
 use a terminal program to connect via USB to the mbed side. */
@@ -12,177 +15,58 @@
 /* This is for testing since it uses the serial port at 9600 bauds to connect to a PC */
 
 /*
-  8255          Parallel    Pin     Bit
-  PC7   /OBF    ->  /ACK        10      6
-  PC6   /ACK    <-  /SLCTIN     17      3
-  PC5   IBF     ->  BUSY        11      7
-  PC4   /STB    <-  /STB        1       0
-
-15 nError       -> p9       not used
-13 Select       -> p10      not used
-12 PE           -> p11      not used
-11 Busy         -> p12      MISO
-10 nAck         -> p13      not used
-
- 1 nStrobe      -> p14      MOSI
-14 nAutoFeed    -> p15      SCLK
-16 nInit        -> p16      not used
-17 nSelectIn    -> p17      not used
-*/
+Doesn't use the Mbed-parallel port PCB
 
-DigitalOut MISO(p12);
-DigitalIn MOSI(p14);
-InterruptIn SCLK(p15);
-
-/*
-CE0 p30  p0.4
-CE1 p29  p0.5
-CE2 p8   p0.6
-CE3 p7   p0.7
-CE4 p6   p0.8
-CE5 p5   p0.9
-CE6 p28  p0.10
-CE7 p27  p0.11
+  SPI          Parallel    Pin     Bit
+  MISO  p6      ->  BUSY        11      7
+  SCK   p7      <-  /AutoFeed   14
+  /SS   p8      <-> D0          2
+  MOSI  p5      <-  /STB        1       0
 */
-BusInOut PtrData(p30,p29,p8,p7,p6,p5,p28,p27);
-
-#define __DOUTBUFSIZE 256
-#define __DINBUFSIZE 256
-char __outstr[__DOUTBUFSIZE];
-char __instr[__DINBUFSIZE];
 
 Serial pc(USBTX, USBRX); // tx, rx
 
 unsigned char rx_data, tx_data;
 
-bool msb_first = true;
-bool edge_falling = false; // false: CPOL = 0, CPHA = 0; true: CPOL = 1, CPHA = 1
-bool byte_ready;
-int bit_count;
-
-void shift_bit(void)
-{
-    if (msb_first)
-    {
-        rx_data = (rx_data << 1) | MOSI;
-        MISO = (tx_data & 0x80) >> 7;
-        tx_data <<= 1;
-    }
-    else
-    {
-        rx_data = (rx_data >> 1) | (MOSI << 7);
-        MISO = tx_data & 1;
-        tx_data >>= 1;
-    }
-    bit_count++;
-    if (bit_count == 8)
-    {
-        byte_ready = true;
-        bit_count = 0;
-    }
-}
-
-void sclk_fall(void)
-{
-    if (edge_falling && (PtrData == 0xfe))
-    {
-        shift_bit();
-    }
-}
-
-void sclk_rise(void)
-{
-   if (!edge_falling && (PtrData == 0xfe))
-   {
-        shift_bit();
-   }
-}
+SPISlave device(p5, p6, p7, p8); // mosi, miso, sclk, ssel
 
 int main()
 {
-unsigned char key;
-bool configure_end = false;
-
-    PtrData.input();
-
-    /* 9600 baud serial port */
-    pc.printf("SPI tester on mbed\r\n\n");
-    
-    MISO = 0;
-    SCLK.fall(&sclk_fall);
-    SCLK.rise(&sclk_rise);
-    SCLK.mode(PullUp);
-    SCLK.enable_irq();
-    
-    byte_ready = false;
-    bit_count = 0;
+    char key;
+    int i = 0;
     
-    pc.printf("Actual configuration\r\n\n");
-    pc.printf("MSB first\r\n");
-    pc.printf("Rising edge clock\r\n\n");
-
+    /* 9600 baud serial port */
+    pc.printf("SPI slave test on mbed\r\n\n");
+    
     pc.printf("Configure\r\n\n");
-    pc.printf("M: MSB first\r\n");
-    pc.printf("L: LSB first\r\n");
-    pc.printf("F: Falling edge clock\r\n");
-    pc.printf("R: Rising edge clock\r\n");
-    pc.printf("G: Go\r\n\n");
+    pc.printf("Mode: 0-3\r\n\n");
 
-    do
-    {
-        key = pc.getc();    
-    
-        switch (key)
-        {
-            case 'M':
-            case 'm':
-                msb_first = true;
-                pc.printf("MSB first\r\n");
-                break;
+    key = pc.getc();    
 
-            case 'L':
-            case 'l':
-                msb_first = false;
-                pc.printf("LSB first\r\n");
-                break;
-                
-            case 'F':
-            case 'f':
-                edge_falling = true;
-                pc.printf("Falling edge clock\r\n");
-                break;
+    switch (key)
+    {
+        case '0':
+        case '1':
+        case '2':
+        case '3':
+            i = key & 0x03;
+            break;
 
-            case 'R':
-            case 'r':
-                edge_falling = true;
-                pc.printf("Rising edge clock\r\n");
-                break;
-                
-            case 'G':
-            case 'g':
-                configure_end = true;
-                break;
-                
-            default:
-            ;                        
-        }
-    } while (!configure_end);
+        default:
+        ;                        
+    }
+    
+    pc.printf("Configure end, mode: %d, begin test\r\n\n",i);
+    device.format(8,i);
+    device.frequency(8000000); //8MHz    
     
-    pc.printf("Configure end, begin test\r\n\n");
-
-    while(1)
-    {
-        if (pc.readable())
-        {
-            tx_data = pc.getc();
+    i = 0;
+    device.reply(0);              // Prime SPI with first reply
+    
+    while(1) {
+        if(device.receive()) {
+            int v = device.read();   // Read byte from master
+            device.reply(v);         // Make this the next reply
         }
-        else
-        {
-            if (byte_ready)
-            {
-                pc.putc(rx_data);
-                byte_ready = false;
-            }
-        }  
     }
 }