mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 281

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

9.3.2.3
Read: anytime
Write: anytime; writes to the reserved bits have no effect
The baud rate divisor equation is as follows:
The baud rate can be calculated with the following equation:
Freescale Semiconductor
SPPR[2:0]
SPR[2:0}
Reset
Field
6:4
2:0
W
R
SPI Baud Rate Preselection Bits — These bits specify the SPI baud rates as shown in
mode, a change of these bits will abort a transmission in progress and force the SPI system into idle state.
SPI Baud Rate Selection Bits — These bits specify the SPI baud rates as shown in
a change of these bits will abort a transmission in progress and force the SPI system into idle state.
SPI Baud Rate Register (SPIBR)
0
0
7
= Unimplemented or Reserved
SPPR2
0
6
BaudRateDivisor
Baud Rate
Figure 9-5. SPI Baud Rate Register (SPIBR)
Table 9-6. SPIBR Field Descriptions
SPPR1
MC9S12E256 Data Sheet, Rev. 1.08
0
5
=
BusClock BaudRateDivisor
SPPR0
=
0
4
SPPR
Description
+
1
3
0
0
2
SPR
Chapter 9 Serial Peripheral Interface (SPIV3)
SPR2
+
0
2
1
Table
SPR1
Table
0
1
9-7. In master mode,
9-7. In master
SPR0
0
0
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