MC68HC08AZ0 Datasheet, PDF (215/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
Serial Communications Interface Module (SCI)
I/O registers
SCI data register
(SCDR)
The SCI data register is the buffer between the internal data bus and the
receive and transmit shift registers. Reset has no effect on data in the
SCI data register.
SCDR
$0018
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
R7
R6
R5
R4
R3
R2
T7
T6
T5
T4
T3
T2
Unaffected by reset
Figure 11. SCI data register (SCDR)
1
Bit 0
R1
R0
T1
T0
R7/T7–R0/T0 — Receive/Transmit data bits
Reading address $0018 accesses the read-only received data bits,
R7–R0. Writing to address $0018 writes the data to be transmitted,
T7–T0. Reset has no effect on the SCI data register.
SCI baud rate
register (SCBR)
The baud rate register selects the baud rate for both the receiver and the
transmitter.
SCBR
$0019
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
SCP1 SCP0
SCR2
0
0
0
0
0
0
= Unimplemented
Figure 12. SCI Baud Rate Register (SCBR)
1
SCR1
0
Bit 0
SCR0
0
SCP1 and SCP0 — SCI Baud Rate Prescaler Bits
These read/write bits select the baud rate prescaler divisor as shown
in Table 8. Reset clears SCP1 and SCP0.
35-sci
MOTOROLA
Serial Communications Interface Module (SCI)
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MC68HC08AZ0
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