twi_master: add routine twiReceiveByteSendAck.

2023-01-30 01:02:31 +01:00
parent 89f403f602
commit 4864d16482
1 changed files with 26 additions and 0 deletions
--- a/avr/twimaster.asm
+++ b/avr/twimaster.asm
@@ -340,6 +340,32 @@ twiReceiveByte_error:



+; ---------------------------------------------------------------------------
+; twiReceiveByteSendAck
+;
+; Read a byte from the bus. Sends ACK bit.
+;
+; IN:
+; OUT:
+; - CARRY flag set: okay, cleared on error
+; - R16: byte received
+; USED: R16, R17, R18, R22
+
+twiReceiveByteSendAck:
+  rcall twiReceiveByte
+  brcc twiReceiveByteSendAck_error
+  push r16
+    clr r16
+    rcall twiWriteBit  ; send ACK (R16, R22)
+  pop r16
+  sec
+  ret
+twiReceiveByteSendAck_error:
+  clc
+  ret
+
+
+
 TWI_Master_ScanNext:
  in r15, SREG
  cli