Norimasa Okamoto
LPC800-MAX RGB demo using SCT and MRT
LPC800-MAX RGB demo using State-Configurable Timer(SCT) and Multi-Rate Timer(MRT).
http://www.youtube.com/watch?v=PABxoWZB0YM
Revision 1:4e19f154ec21, committed 2013-10-14
- Comitter:
- va009039
- Date:
- Mon Oct 14 03:59:30 2013 +0000
- Parent:
- 0:f86c572491c3
- Commit message:
- first commit
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MRT.cpp Mon Oct 14 03:59:30 2013 +0000
@@ -0,0 +1,53 @@
+#include "MRT.h"
+
+MRT::MRT(int channel)
+{
+ static bool insted = false;
+
+ if (!insted) {
+ inst();
+ insted = true;
+ }
+
+ _ch = &LPC_MRT->Channel[channel];
+ _ch->CTRL |= (1<<1); // one-shot
+}
+
+void MRT::inst()
+{
+ LPC_SYSCON->SYSAHBCLKCTRL |= (1<<10); // enable MRT
+ LPC_SYSCON->PRESETCTRL |= (1<<7); // reset MRT
+ us_clk = SystemCoreClock / 1000000;
+}
+
+void MRT::write(uint32_t interval)
+{
+ _ch->INTVAL = interval | (1<<31); // and LOAD
+ _ch->STAT |= 0x01;
+}
+
+int MRT::status()
+{
+ return (_ch->STAT & 1) ? IDLE : RUNNING;
+}
+
+void MRT::wait_ms(uint32_t timeout_ms)
+{
+ wait_raw(us_clk * 1000 * timeout_ms);
+}
+
+void MRT::wait_us(uint32_t timeout_us)
+{
+ wait_raw(us_clk * timeout_us);
+}
+
+void MRT::wait_raw(uint32_t timeout)
+{
+ write(timeout);
+ while(status() == RUNNING);
+}
+
+uint32_t MRT::read()
+{
+ return _ch->TIMER;
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MRT.h Mon Oct 14 03:59:30 2013 +0000
@@ -0,0 +1,26 @@
+#pragma once
+#include "LPC8xx.h"
+
+class MRT {
+public:
+ MRT(int channel = 0);
+ /** write down counter
+ * @param interval start count
+ */
+ void write(uint32_t interval);
+ /** read down counter
+ */
+ uint32_t read();
+ enum STAT {
+ IDLE,
+ RUNNING,
+ };
+ int status();
+ void wait_ms(uint32_t timeout_ms);
+ void wait_us(uint32_t timeout_us);
+ void wait_raw(uint32_t timeout);
+protected:
+ void inst();
+ MRT_Channel_cfg_Type* _ch;
+ int us_clk;
+};
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/SCT_PWM.cpp Mon Oct 14 03:59:30 2013 +0000
@@ -0,0 +1,99 @@
+#include "SCT_PWM.h"
+
+#define BIT_ON(A) (1<<A)
+
+// http://www.lpcware.com/content/nxpfile/lpc80-sct-cookbook-and-tutorial-code-examples
+
+SCT_PWM::SCT_PWM(int pin, int channel) : ch(channel)
+{
+ static bool insted = false;
+
+ if (!insted) {
+ inst();
+ insted = true;
+ }
+ swm(pin);
+
+ LPC_SCT->EVENT[ch + 1].STATE = LPC_SCT->EVENT[0].STATE;
+ LPC_SCT->EVENT[ch + 1].CTRL = LPC_SCT->EVENT[0].CTRL | (ch+1)<<0; // match 1...5
+
+ LPC_SCT->OUT[ch].SET = BIT_ON(0); // event 0
+ LPC_SCT->OUT[ch].CLR = BIT_ON(ch+1); // event 1...5
+}
+
+void SCT_PWM::inst()
+{
+ LPC_SYSCON->SYSAHBCLKCTRL |= (1<<8); // enable SCT
+ LPC_SYSCON->PRESETCTRL |= (1<<8); // reset SCT
+
+ LPC_SCT->EVENT[0].STATE = BIT_ON(0); // state 0
+ LPC_SCT->EVENT[0].CTRL = (1<<12) | (1<<14);
+
+ LPC_SCT->LIMIT_L |= BIT_ON(0); // event 0
+
+ LPC_SCT->CONFIG |= (1<<0) | (1<<17); // unify, auto limit
+ LPC_SCT->CTRL_L |= (SystemCoreClock/1000000-1)<<5; // set prescaler, SCT clock = 1 MHz
+
+ LPC_SCT->CTRL_L &= ~(1<<2); // unhalt it by clearing bit 2 of CTRL reg
+}
+
+void SCT_PWM::swm(int pin)
+{
+ switch(ch) {
+ case 0: // CTOUT_0
+ LPC_SWM->PINASSIGN6 = (LPC_SWM->PINASSIGN6 & 0x00ffffff) | pin<<24;
+ break;
+ case 1: // CTOUT_1
+ LPC_SWM->PINASSIGN7 = (LPC_SWM->PINASSIGN7 & 0xffffff00) | pin<<0;
+ break;
+ case 2: // CTOUT_2
+ LPC_SWM->PINASSIGN7 = (LPC_SWM->PINASSIGN7 & 0xffff00ff) | pin<<8;
+ break;
+ case 3: // CTOUT_3
+ LPC_SWM->PINASSIGN7 = (LPC_SWM->PINASSIGN7 & 0xff00ffff) | pin<<16;
+ break;
+ }
+}
+
+void SCT_PWM::period(float seconds)
+{
+ period_us(seconds * 1000000);
+}
+
+void SCT_PWM::period_ms(int ms)
+{
+ period_us(ms * 1000);
+}
+
+void SCT_PWM::period_us(int us)
+{
+ LPC_SCT->MATCHREL[0].U = us - 1;
+}
+
+void SCT_PWM::pulsewidth(float seconds)
+{
+ pulsewidth_us(seconds * 1000000);
+}
+
+void SCT_PWM::pulsewidth_ms(int ms)
+{
+ pulsewidth_us(ms * 1000);
+}
+
+void SCT_PWM::pulsewidth_us(int us)
+{
+ LPC_SCT->MATCHREL[ch + 1].U = us;
+}
+
+void SCT_PWM::write(float value)
+{
+ LPC_SCT->MATCHREL[ch + 1].U = value * LPC_SCT->MATCHREL[0].U;
+}
+
+float SCT_PWM::read()
+{
+ if (LPC_SCT->MATCHREL[0].U == 0) {
+ return 0.0;
+ }
+ return (float)LPC_SCT->MATCHREL[ch + 1].U / LPC_SCT->MATCHREL[0].U;
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/SCT_PWM.h Mon Oct 14 03:59:30 2013 +0000
@@ -0,0 +1,30 @@
+#pragma once
+#include "LPC8xx.h"
+
+class SCT_PWM {
+public:
+ SCT_PWM(int pin = 7, int channel = 0);
+ void period(float seconds);
+ void period_ms(int ms);
+ void period_us(int us);
+ void pulsewidth(float seconds);
+ void pulsewidth_ms(int ms);
+ void pulsewidth_us(int us);
+ void write(float value);
+ float read();
+ void swm(int pin = 7);
+
+ SCT_PWM& operator= (float value) {
+ write(value);
+ return *this;
+ }
+
+ SCT_PWM& operator= (SCT_PWM& rhs) {
+ write(rhs.read());
+ return *this;
+ }
+
+protected:
+ void inst();
+ int ch;
+};
--- a/main.cpp Mon Oct 15 12:19:12 2012 +0000
+++ b/main.cpp Mon Oct 14 03:59:30 2013 +0000
@@ -1,3 +1,29 @@
+#ifdef TARGET_LPC812
+#include "mbed.h"
+#include "SCT_PWM.h"
+#include "MRT.h"
+
+SCT_PWM r (LED_RED, 0);
+SCT_PWM g (LED_GREEN, 1);
+SCT_PWM b (LED_BLUE, 2);
+
+int main()
+{
+ MRT* mrt = new MRT();
+ r.period(0.001);
+ while(1) {
+ for(float i = 0.0; i < 1.0 ; i += 0.001) {
+ float p = 3 * i;
+ r = 1.0 - ((p < 1.0) ? 1.0 - p : (p > 2.0) ? p - 2.0 : 0.0);
+ g = 1.0 - ((p < 1.0) ? p : (p > 2.0) ? 0.0 : 2.0 - p);
+ b = 1.0 - ((p < 1.0) ? 0.0 : (p > 2.0) ? 3.0 - p : p - 1.0); ;
+ mrt->wait_ms(10);
+ }
+ }
+}
+
+#else
+// http://mbed.org/users/chris/code/app-board-RGB/
#include "mbed.h"
PwmOut r (p23);
@@ -16,4 +42,5 @@
wait (0.01);
}
}
-}
\ No newline at end of file
+}
+#endif
--- a/mbed.bld Mon Oct 15 12:19:12 2012 +0000 +++ b/mbed.bld Mon Oct 14 03:59:30 2013 +0000 @@ -1,1 +1,1 @@ -http://mbed.org/users/mbed_official/code/mbed/builds/cd19af002ccc \ No newline at end of file +http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f \ No newline at end of file