Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256 Manuale Utente
Codici prodotto
DEMO9S12XHY256
Serial Communication Interface (S12SCIV5)
MC9S12XHY-Family Reference Manual, Rev. 1.04
468
Freescale Semiconductor
14.3.2.9
SCI Data Registers (SCIDRH, SCIDRL)
Read: Anytime; reading accesses SCI receive data register
Write: Anytime; writing accesses SCI transmit data register; writing to R8 has no effect
NOTE
If the value of T8 is the same as in the previous transmission, T8 does not
have to be rewritten.The same value is transmitted until T8 is rewritten
have to be rewritten.The same value is transmitted until T8 is rewritten
In 8-bit data format, only SCI data register low (SCIDRL) needs to be
accessed.
accessed.
When transmitting in 9-bit data format and using 8-bit write instructions,
write first to SCI data register high (SCIDRH), then SCIDRL.
write first to SCI data register high (SCIDRH), then SCIDRL.
Module Base + 0x0006
7
6
5
4
3
2
1
0
R
R8
T8
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 14-12. SCI Data Registers (SCIDRH)
Module Base + 0x0007
7
6
5
4
3
2
1
0
R
R7
R6
R5
R4
R3
R2
R1
R0
W
T7
T6
T5
T4
T3
T2
T1
T0
Reset
0
0
0
0
0
0
0
0
Figure 14-13. SCI Data Registers (SCIDRL)
Table 14-13. SCIDRH and SCIDRL Field Descriptions
Field
Description
SCIDRH
7
R8
Received Bit 8 — R8 is the ninth data bit received when the SCI is configured for 9-bit data format (M = 1).
SCIDRH
6
T8
Transmit Bit 8 — T8 is the ninth data bit transmitted when the SCI is configured for 9-bit data format (M = 1).
SCIDRL
7:0
R[7:0]
T[7:0]
R7:R0 — Received bits seven through zero for 9-bit or 8-bit data formats
T7:T0 — Transmit bits seven through zero for 9-bit or 8-bit formats
T7:T0 — Transmit bits seven through zero for 9-bit or 8-bit formats