avr: improved protocol timing for COM2.

- increased waiting time after lowering ATTN line
- lengthten stop bit for cleaner frames (now recognized by PulseView)
- count "NOTFORME" conditions
- introduce definition COM_HALFBIT_LENGTH (I dont' trust value calculations
  in avrasm)
This commit is contained in:
Martin Preuss
2024-09-29 14:59:19 +02:00
parent b93ead5e5f
commit 5767c1307d
9 changed files with 88 additions and 30 deletions

View File

@@ -47,7 +47,8 @@
; ---------------------------------------------------------------------------
; COM module
.equ COM_BIT_LENGTH = 52000 ; 104000=9600, 52000=19200, 26000=38400
.equ COM_BIT_LENGTH = 52000 ; 104000ns=9600, 52000ns=19200, 26000ns=38400
.equ COM_HALFBIT_LENGTH = 26000 ; see https://de.wikipedia.org/wiki/Universal_Asynchronous_Receiver_Transmitter
.equ COM_DDR_DATA = DDRA
.equ COM_PORT_DATA = PORTA