From: Nathaniel Wesley Filardo <nwf@smaug.priv.ietfng.org>
Date: Wed, 24 Mar 2010 04:21:31 +0000 (-0400)
Subject: Add support for, and switch output to, OC2B PWMDAC
X-Git-Url: https://hydra-www.ietfng.org/gitweb/?a=commitdiff_plain;h=f99dc9f50338ec5aa7970504fd6f2cd1caeafac7;p=acmetensortoys-chiptunes

Add support for, and switch output to, OC2B PWMDAC
---

diff --git a/target/asm.S b/target/asm.S
index 81459e2..505922f 100644
--- a/target/asm.S
+++ b/target/asm.S
@@ -43,6 +43,12 @@ __vector_14:
 		out	_SFR_IO_ADDR(TARGET_AUDIO_PORT), r24        ;		1
 #endif
 
+ 		; ---------------------------------------------
+
+#ifdef TARGET_AUDIO_PWM_OC2B
+		sts  OCR2B, r24			;				2
+#endif
+
 		; ---------------------------------------------
 		; Run the noise shift register.
 		; 31 clocks.
diff --git a/target/config.h b/target/config.h
index 27b9d68..4b0dcf6 100644
--- a/target/config.h
+++ b/target/config.h
@@ -12,9 +12,15 @@
 
 #endif
 
-#define TARGET_AUDIO_PORT	PORTC
-#define TARGET_AUDIO_DDR	DDRC
-#define TARGET_AUDIO_PORT_SHIFT 2
+// #define TARGET_AUDIO_PORT	PORTC
+// #define TARGET_AUDIO_DDR	DDRC
+// #define TARGET_AUDIO_PORT_SHIFT 2
+#undef  TARGET_AUDIO_PORT
+#undef  TARGET_AUDIO_DDR
+#undef  TARGET_AUDIO_PORT_SHIFT
+
+#define TARGET_AUDIO_PWM_OC2B
+
 #define TARGET_LIGHT_PORT	PORTB
 #define TARGET_LIGHT_DDR	DDRB
 #define TARGET_LIGHT_ZERO	0x01
diff --git a/target/main.c b/target/main.c
index 03f7719..67780e8 100644
--- a/target/main.c
+++ b/target/main.c
@@ -367,6 +367,13 @@ int main() {
 
 	TIMSK0 = 0x02;
 
+#ifdef TARGET_AUDIO_PWM_OC2B
+        TCCR2A = (1 << COM2B1) | (1 << WGM21) | (1 << WGM20);
+        TCCR2B = (1 << CS20);
+        OCR2B = 0;
+        DDRD |= (1 << 3);
+#endif
+
 	asm("sei");
 	for(;;) {
 		while(!timetoplay);