221
Block Diagram: Figure 10.3 shows a block diagram of SCI3.
SCK
TXD
RXD
3
TSR
RSR
RDR
TDR
SSR
SCR3
SMR
BRR
BRC
RSR:
RDR:
TSR:
TDR:
SMR:
SCR3:
SSR:
BRR:
BRC:
External
clock
Baud rate
generator
Internal clock
(ø/64, ø/16, ø/4, ø)
Clock
Transmit/receive
control
Internal data bus
Interrupt
requests
(TEI, TXI,
RXI, ERI)
Legend:
Receive shift register
Receive data register
Transmit shift register
Transmit data register
Serial mode register
Serial control register 3
Serial status register
Bit rate register
Bit rate counter
Figure 10.3 SCI3 Block Diagram