add better delay function, optimize carry-increment

src/blink_led.c

@@ -8,7 +8,7 @@
 // disable watchdog,
 // and DO NOT disable low voltage programming.
 // The rest of fuses are left as default.
-__code uint16_t __at (_CONFIG1) __configword = _WDTE_OFF & _BOREN_ON & _CP_OFF;
+__code uint16_t __at (_CONFIG1) __configword = _FOSC_INTOSC & _CLKOUTEN_OFF & _WDTE_OFF & _BOREN_ON & _CP_OFF;
 
 #define LED_PORT PORTCbits.RC5
 #define LED_TRIS TRISCbits.TRISC5
@@ -18,25 +18,63 @@ __code uint16_t __at (_CONFIG1) __configword = _WDTE_OFF & _BOREN_ON & _CP_OFF;
 // RA5, RA4, RC2, RC3
 // 'input' pin: RC5
 
-// Uncalibrated delay, just waits a number of for-loop iterations
+// microsecond delay.
-void delay(uint16_t iterations)
+static inline void delay(uint8_t us)
 {
-	uint16_t i;
+  TMR1L = 0;
-	for (i = 0; i < iterations; i++) {
+  while(TMR1L < us);
-		// Prevent this loop from being optimized away.
-		__asm nop __endasm;
-	}
 }
-
+#define ADDTOUINT16(REG, LIT) __asm \
+  BANKSEL REG \
+  MOVLW LIT \
+  ADDWF _##REG##L, F \
+  CLRW \
+  ADDWFC _##REG##H, F \
+  __endasm
+#define SUBFROMUINT16(REG, LIT) __asm \
+  BANKSEL REG \
+  MOVLW LIT \
+  SUBWF _##REG##L, F \
+  CLRW \
+  SUBWFB _##REG##H, F \
+  __endasm
+#define PPSO_PWM1 3
 void main(void)
 {
-	LED_TRIS = 0; // Pin as output
+  OSCCON = 0xf0;
-	LED_PORT = 0; // LED off
+  TRISC = 0;
-	
+  T1CON = 0x31; // timer1 at 1 mhz, so 1us
-	while (1) {
+  ANSELA = 0;
-		LED_PORT = 1; // LED On
+  TRISA = 0;
-		delay(30000); // ~500ms @ 4MHz
+  //SLRCONC = 0;
-		LED_PORT = 0; // LED Off
+  LED_PORT = 0;
-		delay(30000); // ~500ms @ 4MHz
+    PWM1CLKCON = 0x00;  // From Fosc w/o prescaler
-	}
+    PWM1PRH = PWM1PRL = 0xFF; // period: 32 mhz / 65535 = 488 Hz
+    PWM1PH     = 0;
+    PWM1DCH = PWM1DCL = 0;
+    PWM1OF     = 0;
+    
+
+    PWM1INTE   = 0x00;  // no interrupts enabled
+    PWM1INTF   = 0x00;  // clear interrupt flag
+    PWM1LDCON  = 0x80;  // load armed
+    PWM1OFCON  = 0x00;  // independent run mode
+    PWM1CON    = 0x80;  // enable, standard PWM mode, active high output
+
+    RC5PPS = PPSO_PWM1;
+
+
+    while(1) {
+      while (PWM1DCL < 0xFF || PWM1DCH < 0xFE) {
+        ADDTOUINT16(PWM1DC, 1);
+          
+        PWMLD = 1;
+        delay(50);
+      }
+      while (PWM1DCL > 0 || PWM1DCH > 0) {
+        SUBFROMUINT16(PWM1DC, 1);
+        PWMLD = 1;
+        delay(50);
+      }
+    }
 }

src/sdcc.nix

@@ -1,19 +1,19 @@
-{ stdenv, fetchurl, bison, flex, boost, texinfo, autoconf, gputils ? null, disabled ? [] }:
+{ stdenv, fetchurl, bison, flex, boost, texinfo, autoconf, zlib, gputils ? null, disabled ? [] }:
 let
   allDisabled = (if gputils == null then [ "pic14" "pic16" ] else []) ++ disabled;
   # choices: mcs51 z80 z180 r2k r3ka gbz80 tlcs90 ds390 ds400 pic14 pic16 hc08 s08 stm8
   inherit (stdenv) lib;
 in
 stdenv.mkDerivation rec {
-  version = "3.7.0";
+  version = "3.8.0";
   name = "sdcc-${version}";
 
   src = fetchurl {
     url = "mirror://sourceforge/sdcc/sdcc-src-${version}.tar.bz2";
-    sha256 = "13llvx0j3v5qa7qd4fh7nix4j3alpd3ccprxvx163c4q8q4lfkc5";
+    sha256 = "08dvvdxd99hb50wvs8m986v3scfj1rdjw18js7pk5n3vxf6nccdk";
   };
 
-  buildInputs = [ bison flex boost texinfo gputils autoconf ];
+  buildInputs = [ bison flex boost texinfo gputils autoconf zlib ];
 
   configureFlags = ''
     ${lib.concatMapStringsSep " " (f: "--disable-${f}-port") allDisabled}