Notes On Switching From Sck Pins To Port Pins - Renesas H8S Family Hardware Manual

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 13.38.

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

1. Transmission end

Figure 13.38 Switching from SCK Pins to Port Pins

Section 13 Serial Communication Interface (SCI)

Low pulse of half a cycle

4. Low pulse output

Rev. 1.00 Mar. 12, 2008 Page 495 of 1178

REJ09B0403-0100