Ssio Operation - Intel 8XC196NT User Manual

Table 8-2. SSIO Port Control and Status Registers (Continued)
Mnemonic Address
INT_PEND1 0012H
P6_DIR 1FD2H
P6_MODE 1FD1H
P6_PIN 1FD7H
P6_REG 1FD5H
SSIO_BAUD 1FB4H
SSIO0_BUF 1FB0H
SSIO1_BUF 1FB2H
SSIO0_CON 1FB1H
SSIO1_CON 1FB3H
NOTE: Always write zeros to the reserved bits in these registers.
8.3

SSIO OPERATION

Each SSIO channel can be configured as either master or slave and as either transmitter or receiv-
er, allowing the channels to communicate in several bidirectional, single-byte transfer modes
(Figure 8-2). A master device transmits a clock signal; a slave device receives a clock signal.
SYNCHRONOUS SERIAL I/O (SSIO) PORT
Interrupt Pending 1
When set, SSIO0 indicates a pending channel 0 transfer interrupt.
When set, SSIO1 indicates a pending channel 1 transfer interrupt.
Port 6 Direction
This register selects the direction of each port 6 pin. Clear P6_DIR.7:4
to configure SD1 (P6.7), SC1 (P6.6), SD0 (P6.5), and SC0 (P6.4) as
high-impedance inputs/open-drain outputs.
Port 6 Mode
This register selects either the general-purpose input/output function or
the peripheral function for each pin of port 6. Set P6_MODE.7:4 to
configure SD1 (P6.7), SC1 (P6.6), SD0 (P6.5), and SC0 (P6.4) for the
SSIO.
Port 6 Pin State
Read P6_PIN to determine the current values of SD1 (P6.7), SC1
(P6.6), SD0 (P6.5), and SC0 (P6.4).
Port 6 Output Data
This register holds data to be driven out on the pins of port 6. For pins
serving as inputs, set the corresponding P6_REG bits; for pins serving
as outputs, write the data to be driven out on the pins to the corre-
sponding P6_REG bits.
SSIO Baud Rate
This register enables and disables the baud-rate generator and selects
the SSIO baud rate.
SSIO Receive and Transmit Buffers
These registers contain either received data or data for transmission,
depending on the communications mode. Data is shifted into this
register from the SD x pin or from this register to the SD x pin, with the
most-significant bit first.
These registers control the communications mode and handshaking
and reflect the status of the SSIO channels.
Description
8-3