MC68HC908GP20 Datasheet, PDF (283/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

18.9.6 SCI Data Register
The SCI data register (SCDR) 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.
Address: $0018
Bit 7
6
Read: R7
R6
Write: T7
T6
Reset:
5
4
3
2
R5
R4
R3
R2
T5
T4
T3
T2
Unaffected by reset
1
Bit 0
R1
R0
T1
T0
Figure 18-15. SCI Data Register (SCDR)
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.
NOTE: Do not use read/modify/write instructions on the SCI data register.
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor
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