SIC63616-(Rev. 1.0) NO. P131
3240-0412
ESIF: Serial interface enable register (P2 port function selection) (FF58H•D0)
Sets P20–P23 to the input/output port for the serial interface.
When "1" is written: Serial interface
When "0" is written: I/O port
Reading: Valid
When "1" is written to the ESIF register, P20, P21, P22 and P23 function as SIN, SOUT, SCLK and SRDY or
SS, respectively.
In slave mode, the P23 terminal functions as SRDY output or SS input terminal, while in master mode, it
functions as the I/O port terminal.
At initial reset, this register is set to "0".
SCTRG: Clock trigger/status (FF58H•D1)
This is a trigger to start input/output of synchronous clock (SCLK).
• When writing
When "1" is written: Trigger
When "0" is written: No operation
When this trigger is supplied to the serial interface activating circuit, the synchronous clock (SCLK) input/
output is started.
As a trigger condition, it is required that data writing or reading on data registers SD0–SD7 be performed
prior to writing "1" to SCTRG. (The internal circuit of the serial interface is initiated through data writing/
reading on data registers SD0–SD7.) In addition, be sure to enable the serial interface with the ESIF register
before setting the trigger.
Supply trigger only once every time the serial interface is placed in the RUN state. Refrain from performing
trigger input multiple times, as leads to malfunctioning.
Moreover, when the synchronous clock SCLK is external clock, start to input the external clock after the
trigger.
• When reading
When "1" is read:
RUN (during input/output the synchronous clock)
When "0" is read:
STOP (the synchronous clock stops)
When this bit is read, it indicates the status of serial interface clock.
After "1" is written to SCTRG, this value is latched till serial interface clock stops (8 clock counts). Therefore,
if "1" is read, it indicates that the synchronous clock is in input/output operation.
When the synchronous clock input/output is completed, this latch is reset to "0".
At initial reset, this bit is set to "0".
ESOUT: SOUT enable register (FF58H•D2)
Enables serial data output from the P21 port.
When "1" is written: Enabled (SOUT)
When "0" is written: Disabled (I/O port)
Reading: Valid
When serial data output is not used, the SOUT output can be disabled to use P21 as an I/O port. When
performing serial output, write "1" to ESOUT to set P21 as the SOUT output port.
At initial reset, this register is set to "0".
SMOD: Operating mode select register (FF59H•D0)
Selects the serial interface operating mode from master mode and slave mode.
When "1" is written: Master mode
When "0" is written: Slave mode
Reading: Valid
Содержание S1C63616
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