Operation Of Serial Output; Figure 8.6-1 Serial Output Settings (When Using Internal Shift Clock); Figure 8.6-2 Serial Output Settings (When Using External Shift Clock) - Fujitsu F2MC-8L Series Hardware Manual

8.6

Operation of Serial Output

The 8-bit serial I/O can perform serial output of 8-bit data synchronized with a shift
clock.
Serial Output Operation
Serial output can operate using an internal or external shift clock. When serial input and output
operation is enabled, the contents of the SDR register are output to the serial data output pin
(SO) at the same time that serial input is performed.
Internal shift clock
Figure 8.6-1 shows the settings required to operate serial output using an internal shift clock.

Figure 8.6-1 Serial Output Settings (When Using Internal Shift Clock)

SMR
SDR
Activating serial output operation outputs the contents of the SDR register to the SO pin,
synchronized with the falling edge of the selected internal shift clock. At this time, the device to
which the data is to be transfered (a serial input) must be waiting for input of the external shift
clock.
External shift clock
Figure 8.6-2 shows the settings required to operate serial output using an external shift clock.

Figure 8.6-2 Serial Output Settings (When Using External Shift Clock)

DDR3
SMR
SDR
Enabling serial output operation outputs the contents of the SDR register to the SO pin,
synchronized with the falling edge of the external shift clock. When serial output completes,
reset the SDR register and enable operation (SMR: SST = "1") promptly for output of the next
data.
When the device being communicated with has completed the serial input operation (on the
rising edge), hold the external shift clock at the "H" level while waiting for the next output data
(idle state).
Bit 7 Bit 6 Bit 5 Bit 4
SIOF SIOE SCKE SOE
1
Sets transmit data.
Bit 7 Bit 6 Bit 5 Bit 4
x x x
SIOF SIOE SCKE SOE
0
Sets transmit data.
Bit 3 Bit 2 Bit 1
CKS1 CKS0 BDS
1 Other than "11"
Bit 3 Bit 2 Bit 1
x x x x
CKS1 CKS0 BDS
1 1 1
8.6 Operation of Serial Output
Bit 0
SST
1
: Used bit
1 : Set "1".
Bit 0
0
SST
: Used bit
1
x : Unused bit
1 : Set "1".
0 : Set "0".
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