Shift Edge - Philips CEM2100/00 Service Manual

(2) External clock
When an external clock is selected by setting SIO2CR<SCK> to "111B", the clock via the
pin from an external source is used as the serial clock.
To ensure shift operation, the serial clock pulse width must be 4/fc or more for both "H" and "L"
levels.
SCK2

15.3.1.2 Shift edge

The leading edge is used to transmit data, and the trailing edge is used to receive data.
(1) Leading edge shift
Data is shifted on the leading edge of the serial clock (falling edge of the
(2) Trailing edge shift
Data is shifted on the trailing edge of the serial clock (rising edge of the
SIO2CR<SIOS>
pin
SCK 2
Shift register 01234567 *0123456
Shift out
Bit7
SO2 pin
SIO2CR<SIOS>
pin
SCK2
Bit7
SI2 pin
Shift register ********
pin
t SCKL
Figure 15-3 External Clock
**012345 ***01234 ****0123
Bit6
Bit5
(a) Leading edge shift (Example of MSB transfer)
Bit6 Bit5
67****** 567*****
7*******
(b) Trailing edge shift (Example of MSB transfer)
Figure 15-4 Shift Edge
Page 181
t SCKH
t SCKL, t SCKH > 4/fc
*****012 ******01
Bit4 Bit3 Bit2
Bit4 Bit3 Bit2
4567**** 34567*** 234567**
T5CL8
SCK2
pin input/output).
SCK2
pin input/output).
SCK2
*******0 ********
Bit1 Bit0
Bit1 Bit0
1234567* 01234567