M68HC12A4EVB Freescale Semiconductor, M68HC12A4EVB Datasheet - Page 200

• Manufacturer Part Number: M68HC12A4EVB
• Manufacturer: Freescale Semiconductor

Specifications of M68HC12A4EVB

• Lead Free Status / Rohs Status: Not Compliant

Serial Interface
14.2.3.6 SCI Data Register
Read: Anytime
Write: Varies on a bit by bit basis
R8 — Receive Bit 8
T8 — Transmit Bit 8
R7T7–R0T0 — Receive/Transmit Data Bits 7 to 0
200
Write has no meaning or effect.
This bit is the ninth serial data bit received when the SCI system is configured for 9-data-bit operation.
Write anytime.
This bit is the ninth serial data bit transmitted when the SCI system is configured for 9-data-bit
operation. When using 9-bit data format, this bit does not have to be written for each data word. The
same value is transmitted as the ninth bit until this bit is rewritten.
Reads access the eight bits of the read-only SCI receive data register (RDR). Writes access the eight
bits of the write-only SCI transmit data register (TDR). SC0DRL and SC0DRH form the 9-bit data word
for the SCI. If the SCI is being used with a 7- or 8-bit data word, only SC0DRL needs to be accessed.
If a 9-bit format is used, the upper register should be written first to ensure that it is transferred to the
transmitter shift register with the lower register.
Address:
Address:
Reset:
Reset:
Read:
Write:
Read:
Write:
$00C6
$00C7
R7T7
Bit 7
Bit 7
R8
U
Figure 14-10. SCI Data Register Low (SC0DRL)
Figure 14-9. SCI Data Register High (SC0DRH)
= Unimplemented
R6T6
T8
M68HC12B Family Data Sheet, Rev. 9.1
U
6
6
R5T5
5
0
0
5
U = Unaffected
Unaffected by reset
R4T4
4
0
0
4
R3T3
3
0
0
3
R2T2
2
0
0
2
R1T1
1
0
0
1
Freescale Semiconductor
R0T0
Bit 0
Bit 0
0
0