Figure 10.8A Operation In Sleep Mode (Internal Shift Clock); Figure 10.8B Operation In Stop Mode (Internal Shift Clock); Figure 10.8C Operation During Halt (Internal Shift Clock); States In Each Mode During 8-Bit Serial I/O Operation - Fujitsu F2MC-8L MB89620 Series Hardware Manual

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10.

States in Each Mode during 8-bit Serial I/O Operation

This section describes the operation of the 8-bit serial I/O when the device changes to
sleep or stop mode or an operation halt request occurs during operation.
n Using Internal Shift Clock
l Operation in sleep mode
In sleep mode, serial I/O operation does not halt but transfer continues, as shown in Figure
10.8a.
l Operation in stop mode
In stop mode, serial I/O operation halts and transfer aborts, as shown in Figure 10.8b. As
operation restarts from the point where it halted after wake-up from stop mode, initialize the 8-bit
serial I/O depending on the state of the device with which the 8-bit serial I/O is communicating.
Operation during halt
l
Halting operation during transfer (SMR: SST = "0") halts the transfer and clears the shift clock
counter, as shown in Figure 10.8c. Therefore, the device being communicated with must also be
initialized. In serial output operation, set data to the SDR register again before reactivating.
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CHAPTER 10 8-BIT SERIAL I/O (SERIAL I/O-1 AND SERIAL I/O-2)
SCK output
SST bit
SIOF bit
SO pin output
#0
SLP bit
(STBC register)

Figure 10.8a Operation in Sleep Mode (Internal Shift Clock)

SCK output
SST bit
SIOF bit
SO pin output
#0
STP bit
(STBC register)

Figure 10.8b Operation in Stop Mode (Internal Shift Clock)

SCK output
SST bit
SIOF bit
SO pin output
#0

Figure 10.8c Operation During Halt (Internal Shift Clock)

#1 #2 #3 #4 #5
Wake-up from sleep mode by IRQ7 or IRQ8.
Stop request
#1 #2 #3 #4
Wake-up from stop mode by an external interrupt
Operation halts.
Reset SDR register
#1 #2 #3 #4
Cleared by the program.
Interrupt request
#6 #7
Sleep mode
Oscillation stabili-
zation delay time
Cleared by the program.
Interrupt request
#5 #6 #7
Stop mode
Operation reactivates.
#5 #0 #1
MB89620 series