Datasheet

Section 12 Serial Communication Interface

Rev.7.00 Dec. 24, 2008 Page 448 of 698

REJ09B0074-0700

Sample Procedure for Avoiding Low-Level Output: As this sample procedure temporarily

places the SCK pin in the input state, the SCK/port pin should be pulled up beforehand with an

external circuit.

With DDR = 1, DR = 1, C/A = 1, CKE1 = 0, CKE0 = 0, and TE = 1, make the following

settings in the order shown.

1. End of serial data transmission

2. TE bit = 0

3. CKE1 bit = 1

4. C/A bit = 0 ... switchover to port output

5. CKE1 bit = 0

Bit 7Bit 6

1. End of transmission

3.CKE1= 1

5.CKE1= 0

4.C/A= 0

2.TE= 0

High-level output

SCK/port

Data

C/A

CKE1

CKE0

Figure 12.44 Operation when Switching from SCK Pin Function to Port Pin Function

(Example of Preventing Low-Level Output)