Toshiba TLCS-900/L1 Series Manual page 178

b. Shift edge
Data is transmitted on the leading edge of the clock and received on the
trailing edge.
Leading edge shift
Data is shifted on the leading edge of the serial clock (on the falling edge of the
SCK pin input/output).
Trailing edge shift
Data is shifted on the trailing edge of the serial clock (on the rising edge of the
SCK pin input/output).
SCK pin output
SO pin output
Bit0
Shift register
76543210 *7654321 **765432 ***76543
SCK pin
SI pin
Bit0
Shift register
0*******
********
*: Don't care
Figure 3.10.25 Shift Edge
Bit1 Bit2 Bit3 Bit4
****7654
(a) Leading edge
Bit1 Bit2 Bit3 Bit4
10****** 210***** 3210**** 43210***
(b) Trailing edge
91C824-176
TMP91C824
Bit5 Bit6 Bit7
*****765 ******76 ******7
Bit5 Bit6 Bit7
543210** 6543210* 76543210
2008-02-20