Operation; Figure 10.2 Transfer Format - Renesas H8/3847R Series Hardware Manual

Section 10 Serial Communication Interface
Bit 7: SCI1 module standby mode control (S1CKSTP)
Bit 7 controls setting and clearing of module standby mode for SCI1.
Bit 7
S1CKSTP Description
0 SCI1 is set to module standby mode*
1 SCI1 module standby mode is cleared
Note: * Setting to module standby mode resets SCR1, SCSR1, SDRU, and SDRL.
10.2.3

Operation

Either 8-bit or 16-bit transfer data can be selected as the transfer format. An internal clock or
external clock can be selected as the clock source. When an external clock is used, overrun errors
can be detected.
1. Clock
The serial clock can be selected from 8 internal clocks or an external clock. When an internal
clock is selected, the SCK
mode is set (SNC1, SNC0 = 10 in SCR1), the clock selected by bits CKS2 to CKS0 (φ/1024 to
φ
/4) is output continuously from the SCK
W
functions as the clock input pin.
2. Data Transfer Format
The SCI1 transfer format is shown in figure 10.2. LSB-first transfer is used (i.e. transmission and
reception are performed starting with the least significant bit of the transfer data). Transfer data is
output from one falling edge of the serial clock until the next falling edge. Receive data is latched
at the rising edge of the serial clock.
SCK
1
SO /SI Bit 0
1 1
Rev. 6.00 Aug 04, 2006 page 340 of 680
REJ09B0145-0600
pin functions as the clock output pin. When continuous clock output
1
pin. When an external clock is selected, the SCK
1
Bit 1 Bit 2 Bit 3

Figure 10.2 Transfer Format

Bit 4 Bit 5 Bit 6
(initial value)
pin
1
Bit 7