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MSM66573 Family User's Manual
Chapter 12 Serial Port Functions
12.5.3 Example of SIO1-related Register Settings
12.5.3.1 UART Mode Settings
Transmit settings
(1)
Port 8 mode register (P8IO)
If TXD8 (transmit data output) is to be used, set bit 1 (P8IO1) to "1" to configure that port
as an output. If the baud rate clock is to be input externally, reset bit 2 (P8IO2) to "0" to
configure that port as an input.
(2)
Port 8 secondary function control register (P8SF)
If TXD1 (transmit data output) is to be used, set bit 1 (P8SF1) to "1" to configure that port
as a secondary function output. If the baud rate clock is to be input externally, specify with
bit 2 (P8SF2) whether the input will be pulled-up.
(3)
SIO1 transmit control register (ST1CON)
Reset bit 0 (ST1MOD) to "0" to change the mode to UART mode. Specify the transmit data
length with bit 1 (ST1LN). Specify the stop bit length with bit 3 (ST1STB). Specify whether
there is parity with bit 4 (ST1PEN). If parity is selected, specify the parity bit logic with bit
5 (ST1ODD). With bit 6 (TR1MIE), specify whether interrupt requests are enabled or
disabled when a transmit buffer empty signal occurs. With bit 7 (TR1NIE), specify whether
interrupt requests are enabled or disabled when a transmit complete signal occurs.
(4)
SIO1 receive control register (SR1CON)
Specify with bit 2 (S1EXC) whether the baud rate clock is internal (overflow output of timer
4) or external (RXC1).
(5)
SIO1 transmit-receive buffer register (S1BUF)
Transmission is started by writing the transmit data to S1BUF.
Receive settings
(1)
Port 8 mode register (P8IO)
If RXD1 (receive data input) is to be used, reset bit 0 (P8IO0) to "0" to configure that port
as an input. If the baud rate clock is to be input externally, reset bit 2 (P8IO2) to "0" to
configure that port as an input.
(2)
Port 8 secondary function control register (P8SF)
Specify with bit 1 (P8SF0) whether the RXD1 pin will be pulled-up. If the baud rate clock
is to be input externally, specify with bit 2 (P8SF2) whether the input will be pulled-up.