MC68HC08AZ32A Datasheet, PDF (258/456 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Serial Peripheral Interface (SPI)
16.13.3 SPI Data Register (SPDR)
The SPI data register is the read/write buffer for the receive data register
and the transmit data register. Writing to the SPI data register writes data
into the transmit data register. Reading the SPI data register reads data
from the receive data register. The transmit data and receive data
registers are separate buffers that can contain different values. See
Figure 16-2.
SPDR
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
R7
R6
R5
R4
R3
R2
T7
T6
T5
T4
T3
T2
Indeterminate after reset
Figure 16-14. SPI Data Register (SPDR)
1
Bit 0
R1
R0
T1
T0
R7:R0/T7:T0 — Receive/Transmit Data Bits
NOTE: Do not use Read-modify-write instructions on the SPI data register since
the buffer read is not the same as the buffer written.
Technical Data
258
MC68HC08AZ32A — Rev 1.0
Serial Peripheral Interface (SPI)
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