HD64F3048VTF8 Datasheet, PDF (542/903 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip

Section 13 Serial Communication Interface
Sample Procedure for Preventing 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
SCK/port
Data
Bit 6
TE
C/A
CKE1
1. End of transmission
Bit 7
2. TE = 0
3. CKE1 = 1
High-level output
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. 3.00 Sep 27, 2006 page 514 of 872
REJ09B0325-0300