NEC mPD780065 Series Preliminary User's Manual page 246

Figure 14-19. Busy Signal and Wait Release (when BUSY00 = 0)
SCK1
SO1
D7
SI1 D7 D6 D5 D4 D3 D2 D1 D0
BUSY
(active high)
(b) Strobe control option
Strobe control is a function for synchronizing data transmission/reception between the master and slave
devices. The master device outputs the strobe signal from the STB/P80 pin when 8-bit transmission/
reception has been completed. By this signal, the slave device can determine the timing of the end of
data transmission. Therefore, synchronization is established even if a bit shift occurs because noise is
superimposed on the serial clock, and transmission of the next byte is not affected by the bit shift.
To use the strobe control option, the following conditions must be satisfied:
• Bit 5 (ATE0) of the serial operating mode register 1 (CSIM1) is set to 1.
• Bit 2 (STRB0) of the automatic data transmit/receive control register (ADTC0) is set to 1.
A strobe signal is output from the STB/P80 pin for the duration of 1 clock in synchronization with the falling
of the ninth serial clock.
Figure 14-20 shows the operation timing when the strobe control option is used.
Figure 14-20. Operation Timing When Strobe Control Option Is Used
SCK1
SO1
D7 D6 D5 D4 D3 D2 D1 D0
SI1
D7 D6 D5 D4 D3 D2 D1 D0
STB
CSIIF1
246
CHAPTER 14 SERIAL INTERFACE (SIO1)
D6 D5 D4 D3 D2 D1 D0
If made inactive
immediately after
sampled
Strobe signal output
Preliminary User's Manual U13420EJ2V0UM00
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
1.5 clock (min.)
Wait
Busy input released
Busy input valid
D7 D6 D5 D4 D3 D2 D1
D7 D6 D5 D4 D3 D2 D1
Strobe signal output
D0
D0