MC68HC705C9A Datasheet, PDF (60/118 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface (SCI)
9.4 SCI Transmitter Features
Features of the SCI transmitter include:
• Transmit data register empty flag
• Transmit complete flag
• Send break
INTERNAL BUS
$0011
TRANSMIT
DATA
REGISTER
SCI INTERRUPT
+
$0011
RECEIVE
DATA
REGISTER
&
&
&
&
$000F
SCCR2
TDO
PIN
TRANSMIT
DATA SHIFT
REGISTER
+
TIE
TCIE
RIE
ILIE
7
6
5
4
RECEIVE
DATA SHIFT
REGISTER
RDI
PIN
TE 3
RE 2
SBK 1
RWU 0
SCSR
$0010
7
6
5
4
32
1
TRDE TC RDRF IDLE OR NF FE
WAKEUP
UNIT
TE
SBK
7
TRANSMITTER
CONTROL
FLAG
CONTROL
RECEIVER
CONTROL
RECEIVER
CLOCK
7
65
4
32
1
0 SCCR1
R8 T8
M WAKE
$000E
Figure 9-1. Serial Communications Interface Block Diagram
NOTE
The serial communications data register (SCI SCDR) is controlled by the
internal R/W signal. It is the transmit data register when written to and the
receive data register when read.
MC68HC05C9A Advance Information Data Sheet, Rev. 4.1
60
Freescale Semiconductor