Hardware manual

Microcomputer Technical Q&A
126
2. Synchronous mode
a. When TSR contains transmit data (see figure below)
When SCK clock source is internal clock: 2 states
When SCK clock source is external clock: 1.5 to 2.5 states
Bit 6 Bit 7
Serial clock
Transmit
data
TDRE
b. When TSR does not contain transmit data (see figure below)
φ
Internal write
signal
TDRE
2.5 states
T1 T2 T3