Revision 0:7953b8ea1d53, committed 2012-01-15

Comitter:

ms523

Date:

Sun Jan 15 15:11:31 2012 +0000

Child:

1:e4104703c457

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jan 15 15:11:31 2012 +0000
@@ -0,0 +1,66 @@
+#include "mbed.h"
+
+SPI my_spi(p5, p6, p7);
+Serial pc(USBTX,USBRX);
+
+#define TNF 0x02
+#define TNE 0x01
+#define RNE 0x04
+
+/*** My method to write to FeRAM ***/
+void spi_write (unsigned char data) {
+    // First don't write to the FIFO buffer if it is full
+    while (!(LPC_SSP1->SR & TNF))       // While TNF-Bit = 0 (FIFO full)...
+        ;                               // Wait
+    LPC_SSP1->DR = data;                // Write to FIFO buffer
+}
+
+/*** Write a byte to FeRAM ***/
+void write_byte (int address, unsigned char data) {
+    spi_write(0x02);                    // Send write command
+    spi_write(address >> 16);           // Send top address byte to write to
+    spi_write((address >> 8) & 0xFF);   // Send Middle address byte to write to
+    spi_write(address & 0xFF);          // Send Bottom address byte to write to
+    spi_write(data);                    // Send data to be write
+    // Now I need to check that the FIFO transmit buffer is empty exiting the method
+    while (!(LPC_SSP1->SR & TNE))       // While TNE-Bit = 0 (FIFO not empty)...
+        ;                               // Wait
+}
+
+/*** Read a byte from FeRAM ***/
+unsigned char read_byte (int address) {
+    unsigned char my_val = 0;           // Variable to store the read data
+    spi_write(0x03);                    // Send read command
+    spi_write(address >> 16);           // Send top address byte to read from
+    spi_write((address >> 8) & 0xFF);   // Send Middle address byte to read from
+    spi_write(address & 0xFF);          // Send Bottom address byte to read from
+    // Now the buffer is empty send out a dummy byte and read the buffer
+    spi_write(0x00);                    // Send the dummy byte
+    // Now I need to empty the FIFO receive buffer...
+    while (LPC_SSP1->SR & RNE)          // While RNE-Bit = 1 (FIFO receive buffer not empty)...
+        my_val = LPC_SSP1->DR;          // Read the byte in the buffer 
+    return (my_val);                    // Return the last byte read
+}
+
+int main() {
+
+    // Set up the SPI port...
+    my_spi.frequency(32000000);         // 32MHz is the fastest mbed frequency supported by the FeRAM
+    my_spi.format(8,3);                 // Set for mode 3
+    LPC_PINCON->PINSEL0 |= 0x00002000;  // Set up SSEL1
+    wait(0.001);                        // Must wait 1ms after power on before using FeRAM
+    my_spi.write(0x06);                 // Send WREN command to write enable
+
+    // Thought I would wait a bit to get a cleaner scope trace
+    wait_us(2);
+
+    // Write the byte...
+    write_byte (100, 0x4C);
+ 
+    // Thought I would wait a bit again
+    wait_us(2);
+
+    // read the byte and display on TeraTerm  
+    int my_val = read_byte (100);
+    pc.printf(" Value = 0x%X",my_val);
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sun Jan 15 15:11:31 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/5364839841bd