MC68HC708MP16 Datasheet, PDF (276/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

Serial Peripheral Interface Module (SPI)
Table 13-3. SPI Configuration
SPE SPMSTR MODFEN
0
X⁽¹⁾
X
1
0
X
1
1
0
1
1
1
1. X = don’t care
SPI Configuration
Not Enabled
Slave
Master without MODF
Master with MODF
State of SS Logic
General-purpose I/O;
SS ignored by SPI
Input-only to SPI
General-purpose I/O;
SS ignored by SPI
Input-only to SPI
13.13.5 CGND (Clock Ground)
CGND is the ground return for the serial clock pin, SPSCK, and the
ground for the port output buffers. To reduce the ground return path loop
and minimize radio frequency (RF) emissions, connect the ground pin of
the slave to the CGND pin of the master.
13.14 I/O Registers
Three registers control and monitor SPI operation:
• SPI control register (SPCR)
• SPI status and control register (SPSCR)
• SPI data register (SPDR)
Technical Data
276
Serial Peripheral Interface Module (SPI)
MC68HC708MP16 — Rev. 3.1
Freescale Semiconductor