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Chapter 15 Serial Communication Interface (S12SCIV6)
MC9S12ZVM Family Reference Manual Rev. 1.3
578
Freescale Semiconductor
15.4.5
Transmitter
Figure 15-16. Transmitter Block Diagram
15.4.5.1
Transmitter Character Length
The SCI transmitter can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI
control register 1 (SCICR1) determines the length of data characters. When transmitting 9-bit data, bit T8
in SCI data register high (SCIDRH) is the ninth bit (bit 8).
15.4.5.2
Character Transmission
To transmit data, the MCU writes the data bits to the SCI data registers (SCIDRH/SCIDRL), which in turn
are transferred to the transmitter shift register. The transmit shift register then shifts a frame out through
the TXD pin, after it has prefaced them with a start bit and appended them with a stop bit. The SCI data
registers (SCIDRH and SCIDRL) are the write-only buffers between the internal data bus and the transmit
shift register.
PE
PT
H
8
7
6
5
4
3
2
1
0
L
11-Bit Transmit Register
Stop
Star
t
T8
TIE
TDRE
TCIE
SBK
TC
Parity
Generation
MSB
SCI Data Registers
Load from SCIDR
Shift Enab
le
Preamb
le (All 1s)
Break (All 0s)
Transmitter Control
M
Internal Bus
SBR15:SBR4
Transmit baud
÷
16
Bus
Clock
TE
SCTXD
TXPOL
LOOPS
LOOP
RSRC
CONTROL
To Receiver
Transmit
Collision Detect
TDRE IRQ
TC IRQ
SCTXD
SCRXD
(From Receiver)
TCIE
BERRIF
BER IRQ
BERRM[1:0]
generator
SBR3:SBR0
Содержание MC9S12ZVM series
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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 ...