HD64F2638F20J Datasheet, PDF (562/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 13 Serial Communication Interface (SCI)
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
• 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 13-28 Operation when Switching from SCK Pin Function to Port Pin Function
(Example of Preventing Low-Level Output)
Page 512 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010