p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 401

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

15.8.8
When SCK pins are switched to port pins after transmission has completed, pins are enabled for
port output after outputting a low pulse of half a cycle as shown in figure 15.26.
To prevent the low pulse output that is generated when switching the SCK pins to the port pins,
specify the SCK pins for input (pull up the SCK/port pins externally), and follow the procedure
below with DDR = 1, DR = 1, C/A = 1, CKE1 = 0, CKE1 = 0, and TE = 1.
1. End serial data transmission
2. TE bit = 0
3. CKE1 bit = 1
4. C/A bit = 0 (switch to port output)
5. CKE1 bit = 0
Figure 15.27 Prevention of Low Pulse Output at Switching from SCK Pins to Port Pins
SCK/Port
Data
TE
C/A
CKE1
CKE0
SCK/Port
Data
TE
C/A
CKE1
CKE0
Notes on Switching from SCK Pins to Port Pins
Bit 6
Bit 6
Figure 15.26 Switching from SCK Pins to Port Pins
Bit 7
Bit 7
1. Transmission end
1. Transmission end
2. TE = 0
2. TE = 0
3. CKE1 = 1
3. C/A = 0
Section 15 Serial Communication Interface (SCI)
4. Low pulse output
Low pulse of half a cycle
Rev. 1.00 Sep. 21, 2006 Page 363 of 658
4. C/A = 0
High output
5. CKE1 = 0
REJ09B0310-0100