H8S2609 Datasheet, PDF (454/624 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 13 Serial Communication Interface (SCI)
13.9.7 Notes when Switching from SCK Pin to Port Pin
• Problem in Operation: When DDR and DR are set to 1, SCI clock output is used in clocked
synchronous mode, and the SCK pin is changed to the port pin while transmission is ended,
port output is enabled after low-level output occurs for one half-cycle.
When switching the SCK pin to the port pin by making the following settings while DDR = 1,
DR = 1, C/A = 1, CKE1 = 0, CKE0 = 0, and TE = 1, low-level output occurs for one half-
cycle.
1. End of serial data transmission
2. TE bit = 0
3. C/A bit = 0 ... switchover to port output
4. Occurrence of low-level output (see figure 13.38)
SCK/port
Data
Bit 6
TE
C/A
Half-cycle low-level output
1. End of transmission
Bit 7
2. TE = 0
4. Low-level output
3. C/A = 0
CKE1
CKE0
Figure 13.38 Operation when Switching from SCK Pin to Port Pin
Rev. 1.00 Jan. 25, 2008 Page 420 of 586
REJ09B0428-0100