MC68HC908LJ12 Datasheet, PDF (270/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Serial Peripheral Interface Module (SPI)
14.4 Pin Name Conventions and I/O Register Addresses
The text that follows describes the SPI. The SPI I/O pin names are SS
(slave select), SPSCK (SPI serial clock), CGND (clock ground), MOSI
(master out slave in), and MISO (master in/slave out). The SPI shares
four I/O pins with four parallel I/O ports.
The full names of the SPI I/O pins are shown in Table 14-1. The generic
pin names appear in the text that follows.
Table 14-1. Pin Name Conventions
SPI Generic
Pin Names:
MISO
MOSI
SS
SPSCK CGND
Full SPI
Pin Names:
SPI
PTD1/MISO
PTD2/MOSI
PTD0/SS
PTD3/SPSCK
V_SS
Figure 14-1 summarizes the SPI I/O registers.
Addr.
$0010
$0011
$0012
=
Register Name
Bit 7
Read:
SPI Control Register
(SPCR)
Write:
Reset:
SPRIE
0
SPI Status and Control ^Read:
Register Write:
(SPSCR) _Reset:
SPRF
0
Read: R7
SPI Data Register
(SPDR)
Write:
T7
Reset:
6
5
R SPMSTR
0
ERRIE
1
OVRF
0
0
R6
R5
T6
T5
= Unimplemented
4
3
CPOL CPHA
0
MODF
1
SPTE
0
1
R4
R3
T4
T3
Unaffected by reset
R
2
1
SPWOM SPE
0
0
MODFEN SPR1
0
0
R2
R1
T2
T1
= Reserved
Figure 14-1. SPI I/O Register Summary
Bit 0
SPTIE
0
SPR0
0
R0
T0
14.5 Functional Description
Figure 14-2 shows the structure of the SPI module.
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor
Serial Peripheral Interface Module (SPI)
Technical Data
271