h8s-2158 Renesas Electronics Corporation., h8s-2158 Datasheet - Page 518

• Manufacturer Part Number: h8s-2158
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
16.10.8 Notes on Switching from SCK Pins to Port Pins
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 16.43.
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
Rev. 3.00 Jan 25, 2006 page 466 of 872
REJ09B0286-0300
Figure 16.44 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
Bit 6
Bit 6
Figure 16.43 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
4. Low pulse output
Low pulse of half a cycle
4. C/A = 0
High output
5. CKE1 = 0