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Chapter 15 Serial Communication Interface (S12SCIV6)
MC9S12ZVM Family Reference Manual Rev. 1.3
562
Freescale Semiconductor
15.3.2.1
SCI Baud Rate Registers (SCIBDH, SCIBDL)
Read: Anytime, if AMAP = 0.
Write: Anytime, if AMAP = 0.
NOTE
Those two registers are only visible in the memory map if AMAP = 0 (reset
condition).
The SCI baud rate register is used by to determine the baud rate of the SCI, and to control the infrared
modulation/demodulation submodule.
Module Base + 0x0000
7
6
5
4
3
2
1
0
R
SBR15
SBR14
SBR13
SBR12
SBR11
SBR10
SBR9
SBR8
W
Reset
0
0
0
0
0
0
0
0
Figure 15-3. SCI Baud Rate Register (SCIBDH)
Module Base + 0x0001
7
6
5
4
3
2
1
0
R
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
W
Reset
0
1
0
0
0
0
0
0
Figure 15-4. SCI Baud Rate Register (SCIBDL)
Table 15-2. SCIBDH and SCIBDL Field Descriptions
Field
Description
SBR[15:0]
SCI Baud Rate Bits — The baud rate for the SCI is determined by the bits in this register. The baud rate is
calculated two different ways depending on the state of the IREN bit.
The formulas for calculating the baud rate are:
When IREN = 0 then,
SCI baud rate = SCI bus clock / (SBR[15:0])
When IREN = 1 then,
SCI baud rate = SCI bus clock / (2 x SBR[15:1])
Note: The baud rate generator is disabled after reset and not started until the TE bit or the RE bit is set for the
first time. The baud rate generator is disabled when (SBR[15:4] = 0 and IREN = 0) or (SBR[15:5] = 0 and
IREN = 1).
Note: . User should write SCIBD by word access. The updated SCIBD may take effect until next RT clock start,
write SCIBDH or SCIBDL separately may cause baud generator load wrong data at that time,if second
write later then RT clock.
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 ...