M16C6S_09 Datasheet, PDF (105/208 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6S Group
Clock Synchronous serial I/O Mode
Counter Measure for Communication Error Occurs
If a communication error occurs while transmitting or receiving in clock synchronous serial I/O mode,
follow the procedures below.
• Resetting the UiRB register (i=0 to 2)
(1) Set the RE bit in the UiC1 register to “0” (reception disabled)
(2) Set the SMD2 to SMD0 bits in the UiMR register to “000b” (Serial I/O disabled)
(3) Set the SMD2 to SMD0 bits in the UiMR register to “001b” (Clock synchronous serial I/O mode)
(4) Set the RE bit in the UiC1 register to “1” (reception enabled)
• Resetting the UiTB register (i=0 to 2)
(1) Set the SMD2 to SMD0 bits in the UiMR register “000b” (Serial I/O disabled)
(2) Set the SMD2 to SMD0 bits in the UiMR register “001b” (Clock synchronous serial I/O mode)
(3) “1” is written to RE bit in the UiC1 register (reception enabled), regardless of the TE bit in the UiCi
register
(a) CLK Polarity Select Function
Use the UiC0 register (i = 0 to 1)’s CKPOL bit to select the transfer clock polarity. Figure 1.14.2 shows
the polarity of the transfer clock.
(1) When the UiC0 register’s CKPOL bit = 0 (transmit data output at the falling
edge and the receive data taken in at the rising edge of the transfer clock)
CLKi
TXDi
D0 D1 D2 D3 D4 D5 D6 D7
(Note 2)
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
(2) When the UiC0 register’s CKPOL bit = 1 (transmit data output at the rising
edge and the receive data taken in at the falling edge of the transfer clock)
CLKi
(Note 3)
TXDi
D0 D1 D2 D3 D4 D5 D6 D7
RXDi
D0 D1 D2 D3 D4 D5 D6 D7
Note 1: This applies to the case where the UiC0 register’s UFORM bit = 0
(LSB first) and UiC1 register's UiLCH bit = 0 (no reverse).
Note 2: When not transferring, the CLKi pin outputs a high signal.
Note 3: When not transferring, the CLKi pin outputs a low signal.
i = 0 to 1
Figure 1.14.2. Transfer Clock Polarity
Rev.5.01 Dec 10, 2009 page 105 of 201
REJ03B0014-0501