Revision 2:f034e862af1f, committed 2010-12-02

Comitter:

hugozijlmans

Date:

Thu Dec 02 20:55:45 2010 +0000

Parent:

1:2c52307d223f

Commit message:

Added UART0 support over USB mBed1768

Changed in this revision

--- a/LPC1768.h	Thu Dec 02 12:32:18 2010 +0000
+++ b/LPC1768.h	Thu Dec 02 20:55:45 2010 +0000
@@ -10,8 +10,16 @@
 
 // Perhiperal clock select
 #define PCLKSEL0 LPC_SC->PCLKSEL0
+#define PCLK_UART1_1 1 << 9
+#define PCLK_UART1_0 1 << 8
+#define PCLK_UART0_1 1 << 7
+#define PCLK_UART0_0 1 << 6
+#define PCLK_TIMER1_1 1 << 5
+#define PCLK_TIMER1_0 1 << 4
 #define PCLK_TIMER0_1 1 << 3
 #define PCLK_TIMER0_0 1 << 2
+#define PCLK_WDT_1 1 << 1
+#define PCLK_WDT_0 1 << 0
 #define PCLKSEL1 LPC_SC->PCLKSEL1
 #define PCLK_RIT_1 1 << 27
 #define PCLK_RIT_0 1 << 26
@@ -20,12 +28,17 @@
 #define PCONP LPC_SC->PCONP
 #define PCTIM0 1 << 1
 #define PCTIM1 1 << 2
+#define PCUART0 1 << 3
+#define PCUART1 1 << 4
 #define PCRIT 1 << 16
 
 // CLKOUT
 #define CLKSRCSEL LPC_SC->CLKSRCSEL
 #define CCLKCFG LPC_SC->CCLKCFG
 
+// Pin output/input function selection
+#define PINSEL0 LPC_PINCON->PINSEL0
+
 // FI0
 #define FIOSET LPC_GPIO1->FIOSET
 #define FIOCLR LPC_GPIO1->FIOCLR
@@ -52,8 +65,18 @@
 #define T0IR_CR0 1 << 4
 #define T0IR_CR1 1 << 5
 
+// UART0
+#define U0LCR LPC_UART0->LCR
+#define U0DLL LPC_UART0->DLL
+#define U0DLM LPC_UART0->DLM
+#define U0FDR LPC_UART0->FDR
+#define U0FCR LPC_UART0->FCR
+#define U0THR LPC_UART0->THR
+#define U0RBR LPC_UART0->RBR
+#define U0IER LPC_UART0->IER
+#define U0IIR LPC_UART0->IIR
+
 // RIT
-
 #define RICOMPVAL LPC_RIT->RICOMPVAL
 #define RICTRL LPC_RIT->RICTRL
 #define RITINT 1 << 0

--- a/MCPWM.c	Thu Dec 02 12:32:18 2010 +0000
+++ b/MCPWM.c	Thu Dec 02 20:55:45 2010 +0000
@@ -3,13 +3,14 @@
 #include "cmsis_nvic.h"
 #include "MCPWM.h"
 #include "LPC1768.h"
+#include "main.h"
 
 void MCPWM_init(void) {
 
     // Make the timer overload at 2000 (96MHz / 2000 = 48kHz)
     // Set the value to 1999 --> hex 7CF
-    MCLIM0 = 0x000007CF;
-    MCLIM1 = 0x000007CF;
-    MCLIM2 = 0x000007CF;
+    MCLIM0 = MCPWM_DIV;
+    MCLIM1 = MCPWM_DIV;
+    MCLIM2 = MCPWM_DIV;
 
 }
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UART0.c	Thu Dec 02 20:55:45 2010 +0000
@@ -0,0 +1,143 @@
+#include "LPC17xx.h"
+#include "core_cm3.h"
+#include "cmsis_nvic.h"
+#include "UART0.h"
+#include "main.h"
+#include "LPC1768.h"
+
+void UART0_interrupt_enable(void) {
+
+    // Enable UART0 interrupt
+    NVIC_EnableIRQ(UART0_IRQn);
+}
+
+void UART0_interrupt_disable(void) {
+
+    // Disable UART0 interrupt
+    NVIC_DisableIRQ(UART0_IRQn);
+}
+
+void UART0_IRQHandler(void) {
+
+    // Determine the cause of the interrupt
+
+    // If THRE then buffer is empty
+    if ((U0IIR & 0x2) == 0x2)
+        i_flags.UART0_tx_idle = 1;
+
+    // If receive buffer contains a byte
+    if ((U0IIR & 0x8) == 0x8) {
+        i_flags.UART0_rx_idle = 0;
+        UART0_rx_interrupt_disable();
+    }
+
+    // Clear the UART0 interrupt
+    NVIC_ClearPendingIRQ(UART0_IRQn);
+
+}
+
+void UART0_init(void) {
+
+    // Set UART0 interrupt priority
+    NVIC_SetPriority(UART0_IRQn, 12);
+
+    // Set RXD0/TXD0 to function UART0
+    PINSEL0 &= ~(0xF0);
+    PINSEL0 |= 0x50;
+
+    // Select the UART0 clk
+    UART0_select_clk();
+
+    // Power the UART0
+    PCONP |= PCUART0;
+
+    // Set the UART0 Line Control Register
+    U0LCR &= 0;
+    U0LCR |= (1 << 1) | (1 << 0) // 8 bit
+             | (1 << 2)            // 1 stop bit
+             | (0 << 3)            // disable parity
+             | (1 << 5) | (0 << 4) // force 1 stick parity
+             | (0 << 6)            // disable break control
+             | (1 << 7);           // divisor access bit enable
+
+    // Set Baudrate 115200
+    // DIVADDVAL 3
+    // MULVAL 10
+    // DLL 40
+    // DLM 0
+    // Error 0.1603%
+
+    // Set Fractional Divider Register
+    U0FDR = 0xA3;
+
+    // Set Baudrate divisor
+    U0DLL = 40;
+    U0DLM = 0;
+
+    // Set divisor access bit 0
+    U0LCR &= ~(1 << 7);
+
+    // Set Fifo control register
+    U0FCR &= 0;
+    U0FCR |= (1 << 7) | (1 << 6) // RX Fifo DMA @ 14 bytes
+             | (1 << 3)            // 1 stop bit
+             | (1 << 2)            // disable parity
+             | (1 << 1)            // disable break control
+             | (1 << 0);           // divisor access bit enable
+
+    // Set interrupt enable sources THRE & RBR
+    U0IER |= 3;
+
+    // Set that the TX is idle
+    i_flags.UART0_tx_idle = 1;
+    // Set that the RX is idle
+    i_flags.UART0_rx_idle = 1;
+
+    // Connect the UART0 interrupt to the interrupt handler
+    NVIC_SetVector(UART0_IRQn, (uint32_t)&UART0_IRQHandler);
+
+    UART0_interrupt_enable();
+
+}
+
+void UART0_select_clk(void) {
+
+    // Including work-around described in errata.lpc1768.pdf R04
+
+    PLL0_disconnect();
+
+    PLL0_disable();
+
+    // Timer0 perhiperal clock select (01 = CCLK)
+    PCLKSEL0 &= ~(PCLK_UART0_1 | PCLK_UART0_0);
+    PCLKSEL0 |= PCLK_UART0_0;
+
+    PLL0_enable();
+
+    PLL0_connect();
+
+}
+
+void UART0_write(uint8_t byte) {
+
+    // Send byte to writebuffer
+    U0THR = byte;
+}
+
+uint8_t UART0_read(void) {
+
+    // Read the RX FIFO
+    uint8_t byte = U0RBR;
+    
+    UART0_rx_interrupt_enable();
+    
+    return byte;
+}
+
+void UART0_rx_interrupt_disable(void) {
+    U0IER &= ~(1);
+}
+
+void UART0_rx_interrupt_enable(void) {
+    U0IER |= 1;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UART0.h	Thu Dec 02 20:55:45 2010 +0000
@@ -0,0 +1,14 @@
+#ifndef __UART0_h
+#define __UART0_h
+
+extern void UART0_interrupt_enable(void);
+extern void UART0_interrupt_disable(void);
+extern void UART0_IRQHandler(void);
+extern void UART0_init(void);
+extern void UART0_select_clk(void);
+extern void UART0_write(uint8_t byte);
+extern uint8_t UART0_read(void);
+extern void UART0_rx_interrupt_disable(void);
+extern void UART0_rx_interrupt_enable(void);
+
+#endif
\ No newline at end of file

--- a/main.c	Thu Dec 02 12:32:18 2010 +0000
+++ b/main.c	Thu Dec 02 20:55:45 2010 +0000
@@ -6,6 +6,7 @@
 #include "LPC1768.h"
 #include "MCPWM.h"
 #include "RIT.h"
+#include "UART0.h"
 
 // BSP defines see main.h
 
@@ -24,13 +25,16 @@
 
     // Set the timer0, enable it and connect to ISR
     Timer0_init();
-    
+
     // Set the RIT, enable it and connect to ISR
     RIT_init();
 
     // Initialize MCPWM
     //MCPWM_init();
 
+    // Initialize UART0
+    UART0_init();
+
     // Start the dispatcher
     dispatcher();
 
@@ -38,27 +42,35 @@
 
 void dispatcher(void) {
 
+    int byte;
+
     while (1) {
 
         // When the timer0 interrupt occurred
         if (i_flags.Timer0_int == 1) {
-            if ((FIOPIN & LED1)==LED1)
-                FIOCLR |= LED1;
-            else
-                FIOSET |= LED1;
+            i_flags.Timer0_int = 0;
+        }
 
-            i_flags.Timer0_int = 0;
+        // When the RIT interrupt occurred
+        if (i_flags.RIT_int == 1) {
+            i_flags.RIT_int = 0;
+        }
+
+        // When UART0 TX is idle
+        if (i_flags.UART0_tx_idle == 1) {
+            i_flags.UART0_tx_idle = 0;
         }
         
-        // When the RIT interrupt occurred
-        if (i_flags.RIT_int == 1) {
-            if ((FIOPIN & LED2)==LED2)
-                FIOCLR |= LED2;
+        // When UART0 RX isn't idle
+        if (i_flags.UART0_rx_idle == 0) {
+            i_flags.UART0_rx_idle = 1;
+            byte = UART0_read();
+            if(byte == 'a')
+              FIOSET |= LED1;
             else
-                FIOSET |= LED2;
-
-            i_flags.RIT_int = 0;
-        }
+              FIOCLR |= LED1;
+            UART0_write(byte);
+        }        
     }
 
 }
\ No newline at end of file

--- a/main.h	Thu Dec 02 12:32:18 2010 +0000
+++ b/main.h	Thu Dec 02 20:55:45 2010 +0000
@@ -8,8 +8,10 @@
 #define PLLMULT (PLLCLK/2/EXTCLK)-1
 #define TIMER0_FREQ 2
 #define TIMER0_DIV (SYSCLK/TIMER0_FREQ)-1
-#define RIT_FREQ 2
+#define RIT_FREQ 10
 #define RIT_DIV (SYSCLK/RIT_FREQ)-1
+#define MCPWM_FREQ 48000
+#define MCPWM_DIV (SYSCLK/MCPWM_FREQ)-1
 #define LED_MASK 0x00B40000
 #define LED1 0x00040000
 #define LED2 0x00100000
@@ -22,6 +24,8 @@
   {
     unsigned Timer0_int:1;
     unsigned RIT_int:1;
+    unsigned UART0_tx_idle:1;
+    unsigned UART0_rx_idle:1;
   };
   unsigned char All_Flags;
 } Tinterrupt_flags;