Intel 386 Table 13-3. SSIO Registers , Address Function

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL

13-16

13.3 REGISTER DEFINITIONSTable 13-3 list the registers associated with the SSIO and the following sections contain bit de-scriptions for each register.

Table 13-3. SSIO Registers

Address Function

PINCFG

(read/write) F826H Pin Configurat ion:

Connects the serial receive clock signal (SRXCLK) and the transmit serial

data signal (SSIOTX) to the package pin.

SIOCFG

(read/write) F836H SIO and SSIO Configuration:

Selects the baud-rate generator’s clock sou rce, SERCLK or PSCLK.

CLKPRS

(read/write) F804H Clock Prescale:

Controls the frequency of PSCLK.

SSIOBAUD

(read/write) F484H SSIO Baud-rate Control:

Enables the baud-rate generator a nd determines its baud rate. In master

mode, the transmitter and recei ver are clocked by the baud -rate generator.

SSIOCTR

(read only) F48AH SSIO Baud-rate Count Down:

Indicates whether the baud-rate ge nerator is enabled and reflects t he current

value of the baud-rate down -counter.

SSIOCON1

(read/write) F486H SSIO Control 1:

Enables the transmitter and re ceiver, indicates when the transmit buffer is

empty and the receive buffer is full. Enables or disables the transmitter or

receiver interrupts. SSIOCON1 also indicates two e rror conditions: the

transmit underrun and receiver overf low.

SSIOCON2

(read/write) F488H SSIO Control 2:

Selects whether the transmitter and receiver are in master or slave mode. In

master mode, the baud-rate generator clocks the transmitter or receiver. In

slave mode, an external master clocks the transmitter or receiver. Also

controls the enabling of the Au tomatic Transmit mode.

SSIOTBUF

(read/write) F480H SSIO Transmit Buffer:

Holds the 16-bit data word to transmit. Data is tra nsmitted most-significant b it

first.

SSIORBUF

(read only) F482H SSIO Receive Buffer:

Holds the 16-bit data word received. Data i s received most-significant bit first.