M16C26 Datasheet, PDF (131/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative
Clock Synchronous Serial I/O Mode
and
subject to change.
SINGLE-CHIP 16-BIT
M16C/26 Group
CMOS MICROCOMPUTER
(a) Polarity select function
As shown in Figure 1.15.13, the CLK polarity select bit (bit 6 at addresses 03A416, 03AC16, 037C16)
allows selection of the polarity of the transfer clock.
1. When CLK polarity select bit = 0
CLKi
TXDi
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
D0 D1 D2 D3 D4 D5 D6 D7
Note 1: The CLKi pin level when not
transferring data is H .
2. 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
Note 2: The CLKi pin level when not
transferring data is L .
Figure 1.15.13. Polarity of transfer clock
(b) LSB first/MSB first select function
As shown in Figure 1.15.14, 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”.
1. 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
LSB first
2. When transfer format select bit = 1
CLKi
TXDi
RXDi
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
MSB first
Note: This applies when the CLK polarity select bit = 0 .
Figure 1.15.14. Transfer format
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