UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 494

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

454
Caution When changing from “CTXE = 0, CRXE = 1” to “CTXE = 1, CRXE = 0”, and when changing from
CSIM
“CTXE = 1, CRXE = 0” to “CTXE = 0, CRXE = 1”, ensure that this is not done with a single instruction,
as this will result in misoperation of the serial clock counter, and the first communication after the
change will finish in fewer than 8 bits. Instead, two instructions should be used as shown below.
Example To change “CTXE = 1, CRXE = 0” to “CTXE = 0, CRXE = 1”
CTXE
7
CRXE
6
Figure 17-11 Clocked Serial Interface Mode Register (CSIM) Format
WUP
5
CHAPTER 17 CLOCKED SERIAL INTERFACE
CLR1 CTXE
SET1 CRXE
4
0
MOD1
3
MOD0
2
MOD1
CRXE
CTXE
CLS1
WUP
CLS1
0
1
0
0
1
1
0
0
1
1
1
0
1
0
1
MOD0
CLS0
Interrupt request signal generated after every serial
transfer in each mode.
Interrupt request signal generated only when address
is received in SBI mode.
CLS0
Wake-Up Function Control
Receive Operations
Disabled
Enabled
Transmit Operations
Disabled
Enabled
0
1
0
1
0
1
0
1
0
Operating Mode Transfer Direction Pins Used
3-wire serial I/O
mode
3-wire serial I/O
mode
SBI mode
Setting prohibited
Address
0FF82H
Serial Clock Specification
External clock
Internal clock
Operating Mode Selection Bit
On Reset
00H
Master
Slave
MSB-first
LSB-first
MSB-first
R/W
R/W
TM3/2
f
f
CLK
CLK
/32
/8
SCK Pin
Input
Output
SB0, SCK
SO0, SI0,
SCK0