M37221M4H_15 Datasheet, PDF (31/114 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER

M37221M4H/M6H/M8H/MAH–XXXSP/FP M37221EASP/FP
Serial I/O Mode Register
b7 b6 b5 b4 b3 b2 b1 b0
0
Serial I/O mode register (SM) [Address 00DC16]
B
Name
0, 1 Internal synchronous
clock selection bits
(SM0, SM1)
Functions
b1 b0
0 0: f(XIN)/4
0 1: f(XIN)/16
1 0: f(XIN)/32
1 1: f(XIN)/64
2 Synchronous clock
selection bit (SM2)
3 Serial I/O port
selection bit (SM3)
0: External clock
1: Internal clock
0: P20, P21
1: SCLK, SOUT
4 Fix this bit to “0.”
After reset R W
0 RW
0 RW
0 RW
0 RW
5 Transfer direction
0: LSB first
selection bit (SM5) 1: MSB first
6 ^{Serial input pin}
0: Input signal from SIN pin.
selection bit (SM6) 1: Input signal from SOUT pin.
7 ^{Nothing is assigned. This bit is a write disable bit.}
When this bit is read out, the value is “0.”
0 RW
0 RW
0 R—
Fig. 8.5.3 Serial I/O Mode Register
Rev.1.00 Oct 01, 2002 page 29 of 110
REJ03B0134-0100Z