Figure 10.7A Serial Input Settings (When Using Internal Shift Clock); Figure 10.7B Serial Input Settings (When Using External Shift Clock); Operation Of Serial Input - Fujitsu F2MC-8L MB89620 Series Hardware Manual

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10.

Operation of Serial Input

The 8-bit serial I/O can perform serial input of 8-bit data synchronized with a shift
clock. The operations of 8-bit serial I/O-1 and 8-bit serial I/O-2 are the same.
n Serial Input Operation
Serial input can operate using an internal or external shift clock. When serial output operation is
enabled, the contents of the SDR register are output to the serial data output pin (SO). Serial
input is performed at the same time.
l Internal shift clock
Figure 10.7a shows the settings required to operate serial input using an internal shift clock.

Figure 10.7a Serial Input Settings (When Using Internal Shift Clock)

Starting serial input operation 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.
l External shift clock
Figure 10.7b shows the settings required to operate serial input using an external shift clock.

Figure 10.7b Serial Input Settings (When Using External Shift Clock)

Enabling serial input operation stores the data on 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 the next data (idle
state).
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CHAPTER 10 8-BIT SERIAL I/O (SERIAL I/O-1 AND SERIAL I/O-2)
Bit 7 Bit 6
DDR3
× ×
PDR4
×
1
SMR SIOF SIOE
SDR
Bit 7 Bit 6
DDR3
× ×
PDR4
×
1
SMR SIOF SIOE
SDR
Bit 5 Bit 4 Bit 3 Bit 2
× ×
0
× × ×
SCKE SOE CKS1 CKS0
×
1 Other than "11"
Stores the received data.
Bit 5 Bit 4 Bit 3 Bit 2
× ×
0
× ×
1
SCKE SOE CKS1 CKS0
×
0 1
Stores the received data.
Bit 1 Bit 0
For 8-bit serial I/O-1
× × ×
For 8-bit serial I/O-2
× × ×
BDS SST
: Used bit
1
× : Unused bit
1 : Set "1".
0 : Set "0".
Bit 1 Bit 0
For 8-bit serial I/O-1
× ×
0
For 8-bit serial I/O-2
× × ×
BDS SST
: Used bit
1 1
× : Unused bit
1 : Set "1".
0 : Set "0".
MB89620 series