External/Status interrupt control
WR15
Miscellaneous control bits: baud rate generator, DPLL control, auto
echo
WR14
Lower byte of baud rate time constant
WR13
Lower byte of baud rate time constant
WR12
Clock mode and source control
WR11
Miscellaneous transmitter/receiver control bits, NRZI, NRZ, FM
coding, CRC reset
WR10
Master interrupt control and reset
WR9
Transmit buffer
WR8
Special HDLC Enhancement Register
WR7'
Sync character (2nd byte) or SDLC Flag
WR7
Sync character (1st byte) or SDLC address field
WR6
Transmitter initialization and control
WR5
Transmit/Receive miscellaneous parameters and codes, clock rate,
stop bits, parity
WR4
Receiver initialization and control
WR3
Interrupt vector
WR2
Interrupt control, Wait/DMA request control
WR1
Table 4 --- SCC write register description
For complete information regarding the SCC registers please refer to Zilog's Z85230
technical manual.