M30222 Datasheet, PDF (117/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
M30222 Group
Rev. G
Clock Synchronous Serial I/O Mode
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(a) Polarity select function
As shown in Figure 1.89, the CLK polarity select bit (bit 6 at addresses 03A416, 03AC16, 037C16) allows
selection of the polarity of the transfer clock.
• When CLK polarity select bit = “0”
CLKi
TXDi
D0 D1 D2 D3 D4 D5 D6 D7
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
• When CLK polarity select bit = “1”
CLKi
TXDi
D0 D1 D2 D3 D4 D5 D6 D7
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
Fig. 1.89. Polarity of transfer clock
Note 1: The CLK pin level when not
transferring data is “H”.
Note 2: The CLK pin level when not
transferring data is “L”.
(b) LSB first/MSB first select function
As shown in Figure 1.90, when the transfer format select bit (bit 7 at addresses 03A416, 03AC16,
037C16) = “0”, the transfer format is “LSB first”; when the bit = “1”, the transfer format is “MSB first”.
• When transfer format select bit = “0”
CLKi
TXDi
D0 D1 D2 D3 D4 D5 D6 D7
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
• When transfer format select bit = “1”
CLKi
TXDi
D7 D6 D5 D4 D3 D2 D1 D0
RXDi
D7 D6 D5 D4 D3 D2 D1 D0
Note: This applies when the CLK polarity select bit = “0”.
Fig. 1.90. Transfer format
LSB first
MSB first
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