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Chapter 16 Serial Peripheral Interface (S12SPIV5)
MC9S12ZVM Family Reference Manual Rev. 1.3
604
Freescale Semiconductor
16.3.2.3
SPI Baud Rate Register (SPIBR)
Read: Anytime
Write: Anytime; writes to the reserved bits have no effect
The baud rate divisor equation is as follows:
BaudRateDivisor = (SPPR + 1)
•
2
(SPR + 1)
Eqn. 16-1
The baud rate can be calculated with the following equation:
Baud Rate = BusClock / BaudRateDivisor
Eqn. 16-2
NOTE
For maximum allowed baud rates, please refer to the SPI Electrical
Specification in the Electricals chapter of this data sheet.
Module Base +0x0002
7
6
5
4
3
2
1
0
R
0
SPPR2
SPPR1
SPPR0
0
SPR2
SPR1
SPR0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 16-5. SPI Baud Rate Register (SPIBR)
Table 16-6. SPIBR Field Descriptions
Field
Description
6–4
SPPR[2:0]
SPI Baud Rate Preselection Bits
—
These bits specify the SPI baud rates as shown in
. In master
mode, a change of these bits will abort a transmission in progress and force the SPI system into idle state.
2–0
SPR[2:0]
SPI Baud Rate Selection Bits
—
These bits specify the SPI baud rates as shown in
. In master mode,
a change of these bits will abort a transmission in progress and force the SPI system into idle state.
Table 16-7. Example SPI Baud Rate Selection (25 MHz Bus Clock) (Sheet 1 of 3)
SPPR2
SPPR1
SPPR0
SPR2
SPR1
SPR0
Baud Rate
Divisor
Baud Rate
0
0
0
0
0
0
2
12.5 Mbit/s
0
0
0
0
0
1
4
6.25 Mbit/s
0
0
0
0
1
0
8
3.125 Mbit/s
0
0
0
0
1
1
16
1.5625 Mbit/s
0
0
0
1
0
0
32
781.25 kbit/s
0
0
0
1
0
1
64
390.63 kbit/s
0
0
0
1
1
0
128
195.31 kbit/s
0
0
0
1
1
1
256
97.66 kbit/s
0
0
1
0
0
0
4
6.25 Mbit/s
0
0
1
0
0
1
8
3.125 Mbit/s
0
0
1
0
1
0
16
1.5625 Mbit/s
Содержание MC9S12ZVM series
Страница 116: ...Chapter 2 Port Integration Module S12ZVMPIMV1 MC9S12ZVM Family Reference Manual Rev 1 3 116 Freescale Semiconductor ...
Страница 242: ...Chapter 7 ECC Generation Module SRAM_ECCV1 MC9S12ZVM Family Reference Manual Rev 1 3 242 Freescale Semiconductor ...
Страница 384: ...Chapter 10 Supply Voltage Sensor BATSV3 MC9S12ZVM Family Reference Manual Rev 1 3 384 Freescale Semiconductor ...
Страница 484: ...Chapter 13 Programmable Trigger Unit PTUV2 MC9S12ZVM Family Reference Manual Rev 1 3 484 Freescale Semiconductor ...
Страница 662: ...Chapter 17 Gate Drive Unit GDUV4 MC9S12ZVM Family Reference Manual Rev 1 3 662 Freescale Semiconductor ...
Страница 684: ...Chapter 18 LIN Physical Layer S12LINPHYV2 MC9S12ZVM Family Reference Manual Rev 1 3 684 Freescale Semiconductor ...
Страница 740: ...Chapter 19 128 KB Flash Module S12ZFTMRZ128K512V2 MC9S12ZVM Family Reference Manual Rev 1 3 740 Freescale Semiconductor ...
Страница 756: ...Appendix A MCU Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 756 Freescale Semiconductor ...
Страница 772: ...Appendix D LINPHY Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 772 Freescale Semiconductor ...
Страница 776: ...Appendix E GDU Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 776 Freescale Semiconductor ...
Страница 788: ...Appendix I MSCAN Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 788 Freescale Semiconductor ...
Страница 790: ...Appendix J Package Information MC9S12ZVM Family Reference Manual Rev 1 3 790 Freescale Semiconductor ...