 sttl Synertek 6551 Device Structure
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*
* 6551 Device Structure
*
 org 0
data rmb 1
reset rmb 0 -- Write to this register for soft reset
status rmb 1
command rmb 1
control rmb 1

* status codes
DS_DEV equ %00000000 Disable Device
EN_DEV equ %00000001 Enable Xmitter/Receiver
DS_RIN equ %00000010 Disable Receiver Interrupt
EN_RIN equ %00000000 Enable Receiver Interrupt
NO_RTS equ %00000000 Drop RTS
EN_XIN equ %00000100 Enable Xmit Interrupts
DS_XIN equ %00001000 Disable Xmit Interrupts (RTS good)
*
AC_XBSY equ %00010000 Xmit buffer empty
AC_RBSY equ %00001000 Rcv buffer full
AC_OVRN equ %00000100 Receiver overrun
AC_FE   equ %00000010 Character framing error
AC_PE   equ %00000001 Character parity error
AC_DSR  equ %01000000 DSR status
AC_DCD  equ %00100000 DCD status
