Specifications

Differences vs. ’C240 SCI
8-5 Serial Communications Interface (SCI)
8.1.2 Architecture
The major elements used in full duplex are shown in Figure 8–1, SCI Block
Diagram and include:
- A transmitter (TX) and its major registers (upper half of Figure 8–1)
J SCITXBUF — transmitter data buffer register. Contains data (loaded
by the CPU) to be transmitted
J TXSHF register — transmitter shift register. Loads data from register
SCITXBUF and shifts data onto the SCITXD pin, one bit at a time
- A receiver (RX) and its major registers (lower half of Figure 8–1)
J RXSHF register — receiver shift register. Shifts data in from SCIRXD
pin, one bit at a time
J SCIRXBUF — receiver data buffer register. Contains data to be read
by the CPU. Data from a remote processor is loaded into register
RXSHF and then into registers SCIRXBUF and SCIRXEMU
- A programmable baud generator
- Data-memory-mapped control and status registers
The SCI receiver and transmitter can operate either independently or simulta-
neously.