HD64F3039F18 Datasheet, PDF (414/710 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family / H8/300H Series

Section 11 Serial Communication Interface
2. Usage Note
The procedure shown below should be used to prevent low-level output when switching from
the SCK pin function to the port function.
As this 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
SCK/port
Data
TE
C/A
CKE1
Bit 6
(1) End of transmission
Bit 7
(2) TE = 0
(4) C/A = 0
(3) CKE1 = 1
(5) CKE1 = 0
CKE0
Figure 11.24 Operation when Switching from SCK Pin Function to Port Pin Function
(Preventing Low-Level Output)
Rev.3.00 Mar. 26, 2007 Page 390 of 682
REJ09B0353-0300