3069RF-ZTAT Datasheet, PDF (535/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

• 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
High-level output TE
SCK/port
Data
Bit 6
TE
C/A
CKE1
1. End of transmission
Bit 7
2. TE= 0
3. CKE1= 1
4. C/A= 0
5. CKE1= 0
CKE0
Figure 13.24 Operation when Switching from SCK Pin Function to Port Pin Function
(Example of Preventing Low-Level Output)
Rev. 5.0, 09/04, page 513 of 978