HD6473837H Datasheet, PDF (313/562 Pages) Renesas Technology Corp – Hardware Manual

2. When an SCK₃ function is switched from clock output to general input/output
When stopping data transfer,
a. Issue one instruction to clear bits TE and RE to 0 and to set bits CKE1 and CKE0 in SCR3
to 1 and 0, respectively.
b. Clear bit COM in SCR3 to 0
c. Clear bits CKE1 and CKE0 in SCR3 to 0
Note that special care is also needed here to avoid an intermediate level of voltage from being
applied to SCK₃.
Caution on Switching TxD Function: If pin TxD is used as a data output pin by SCI3 in
synchronous mode and is then switched to a general input/output pin (a pin with a different
function), the pin outputs a high level signal for one system clock (φ) cycle immediately after it is
switched.
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