upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 226

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(2) 3-wire serial I/O mode
226
Remarks 1. Values in parentheses apply when f
(n = 0 to 2)
3-wire serial I/O mode is useful when connecting to a peripheral I/O device that includes a clocked serial interface,
a display controller, etc.
This mode executes data transfers via three lines: a serial clock line (SCKn), serial output line (SOn), and serial
input line (SIn).
(a) Register settings
After reset : 00H
CSIMn
3-wire serial I/O mode is set via serial operation mode register n (CSIMn).
2. Refer to 10.2.2 (1) Serial clock select registers 0 to 2 (CSIS0 to CSIS2), serial operation mode
registers 0 to 2 (CSIM0 to CSIM2) for the SCLn2 bit.
MODEn
CSIEn
SCLn2
CSIEn
1
0
1
0
0
0
0
1
1
1
1
7
R/W
Figure 10-3. Settings of CSIMn (3-Wire Serial I/O Mode)
Operation enable
Transmit/receive mode
Receive-only mode
SCLn1
Shift Register Operation
0
0
1
1
0
0
1
1
6
0
Operation Mode
CHAPTER 10 SERIAL INTERFACE FUNCTION
SCLn0
User’s Manual U12768EJ4V1UD
0
1
0
1
0
1
0
1
Address: CSIM0
5
0
SIOn Operation Enable/Disable Specification
XX
External clock input (SCKn)
When n = 0: TM2 output
When n = 1, 2: TM3 output
fxx/8 (2.5 MHz)
fxx/16 (1.25 MHz)
Setting prohibited
Setting prohibited
fxx/32 (625 kHz)
fxx/64 (312.5 kHz)
= 20 MHz.
CSIM1
CSIM2
Transfer Operation Mode Flag
Count operation enable
SIOn write
SIOn read
4
0
Transfer Start Trigger
Serial Counter
FFFFF2A2H
FFFFF2B2H
FFFFF2C2H
3
0
Clock Selection
MODEn
2
Serial function + port function
Normal output
Port function
SCLn1
SOn Output
1
Port
SCLn0
0