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S912XHZ512F1VAG Datasheet, PDF (602/978 Pages) Freescale Semiconductor, Inc – Covers MC9S12XHZ384, MC9S12XHZ256 | |||
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Chapter 16 Serial Peripheral Interface (S12SPIV4)
16.2.3 SS â Slave Select Pin
This pin is used to output the select signal from the SPI module to another peripheral with which a data
transfer is to take place when it is conï¬gured as a master and it is used as an input to receive the slave select
signal when the SPI is conï¬gured as slave.
16.2.4 SCK â Serial Clock Pin
In master mode, this is the synchronous output clock. In slave mode, this is the synchronous input clock.
16.3 Memory Map and Register Deï¬nition
This section provides a detailed description of address space and registers used by the SPI.
16.3.1 Module Memory Map
The memory map for the SPI is given in Figure 16-2. The address listed for each register is the sum of a
base address and an address offset. The base address is deï¬ned at the SoC level and the address offset is
deï¬ned at the module level. Reads from the reserved bits return zeros and writes to the reserved bits have
no effect.
Register
Name
Bit 7
0x0000
R
SPICR1 W SPIE
0x0001
R
0
SPICR2 W
0x0002
R
0
SPIBR
W
0x0003
SPISR
R SPIF
W
0x0004
R
Reserved W
0x0005
SPIDR
R
Bit 7
W
0x0006
R
Reserved W
0x0007
R
Reserved W
6
SPE
0
SPPR2
0
5
4
3
SPTIE
MSTR
CPOL
0
MODFEN BIDIROE
0
SPPR1
SPPR0
SPTEF
MODF
0
6
5
4
3
= Unimplemented or Reserved
Figure 16-2. SPI Register Summary
2
CPHA
0
SPR2
0
2
1
SSOE
SPISWAI
SPR1
0
1
Bit 0
LSBFE
SPC0
SPR0
0
Bit 0
MC9S12XHZ512 Data Sheet, Rev. 1.06
602
Freescale Semiconductor
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