Operation Of Serial Input; Figure 8.7-1 Serial Input Settings (When Using Internal Shift Clock); Figure 8.7-2 Serial Input Settings (When Using External Shift Clock) - Fujitsu F2MC-8L Series Hardware Manual

8.7

Operation of Serial Input

The 8-bit serial I/O can perform serial input of 8-bit data synchronized with a shift
clock.
Serial Input Operation
Serial input 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 8.7-1 shows the settings required to operate serial input using an internal shift clock.

Figure 8.7-1 Serial Input Settings (When Using Internal Shift Clock)

DDR3
SMR
SDR
Starting serial input operation fetches and stores the value of the serial data input pin (SI) to the
SDR register, synchronized with the rising edge of the selected internal shift clock. At this time,
the device being communicated with (a serial output) must have data set in the SDR register
and be waiting for input of the external shift clock.
External shift clock
Figure 8.7-2 shows the settings required to operate serial input using an external shift clock.

Figure 8.7-2 Serial Input Settings (When Using External Shift Clock)

DDR3
SMR
SDR
Enabling serial input operation fetches and stores the value of the SI pin to the SDR register,
synchronized with the rising edge of the external shift clock. When serial input completes, read
the SDR register and enable operation (SMR: SST = "1") promptly to input the next data.
During this time, hold the external shift clock at the "H" level while waiting for output of the next
Bit 7 Bit 6 Bit 5 Bit 4
x x x
SIOF SIOE SCKE SOE
1
Stores the received data.
Bit 7 Bit 6 Bit 5 Bit 4
x x x
SIOF SIOE SCKE SOE
0
Stores the received data.
Bit 3 Bit 2 Bit 1
x x 0 x
CKS1 CKS0 BDS
x Other than "11"
Bit 3 Bit 2 Bit 1
x x 0 x
CKS1 CKS0 BDS
x 1 1
8.7 Operation of Serial Input
Bit 0
x
SST
1
: Used bit
x : Unused bit
1 : Set "1".
0 : Set "0".
Bit 0
0
SST
1
: Used bit
x : Unused bit
1 : Set 1 .
0 : Set 0 .
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