X-Git-Url: https://hackdaworld.org/gitweb/?p=my-code%2Fatmel.git;a=blobdiff_plain;f=led_plex%2Fport.asm;fp=led_plex%2Fport.asm;h=b5aec4b038258aa30bcc613fb1a518225245e4f7;hp=55e90e2ccf45c3355647a3aadc4fd63a307fc37c;hb=204affb08caa9c97cdd1cc010f5a8fbaa0571992;hpb=87ef21d9eacec01abdbf3306dd2493aecf0b4afb

diff --git a/led_plex/port.asm b/led_plex/port.asm
index 55e90e2..b5aec4b 100644
--- a/led_plex/port.asm
+++ b/led_plex/port.asm
@@ -6,10 +6,20 @@ PORT_INIT:
 	ldi tmp1,0x0f
 	out DDRB,tmp1
 
-	; g, rck, sck -> low / scl -> high
-	ldi tmp1,0x07
-	out PORTB,tmp1
-	sbi PORTB,3
+	; disable hc595 outputs
+	sbi PORTB,0
+
+	; rck -> low
+	cbi PORTB,1
+
+	; clear hc595 registers
+	cbi PORTB,3
+
+	; rck -> high (store shift register data)
+	sbi PORTB,1
+
+	; enable outputs
+	cbi PORTB,0
 
 	; port d 6 -> output
 	sbi DDRD,6
@@ -17,6 +27,9 @@ PORT_INIT:
 	; ser -> low
 	cbi PORTD,6
 
+	; release hc595 register clear
+	sbi PORTB,3
+
 	ret
 
 SET_HC595: