PMC-Sierra manual Serial Interface Description Continued, Spi Modes, Pm25LV512/010, SPI Modes

PMC Pm25LV512/010

SERIAL INTERFACE DESCRIPTION (CONTINUED)

SPI MODES

These devices can be driven by microcontroller with its SPI peripheral running in either of the two following modes: Mode 0 = (0, 0)

Mode 3 = (1, 1)

For these two modes, input data is latched in on the rising edge of Serial Clock (SCK), and output data is

available from the falling edge of Serial Clock (SCK).

The difference between the two modes, as shown in Figure 2, is the clock polarity when the bus master is in Stand-by mode and not transfering data:

-Clock remains at 0 (SCK = 0) for Mode 0 (0, 0)

-Clock remains at 1 (SCK = 1) for Mode 3 (1, 1)

Figure 2. SPI Modes

Mode 0 (0	0)	S C K
Mode 3 (1	1)	S C K
		SI
		S O

Programmable Microelectronics Corp. 6 Issue Date: February, 2004, Rev: 1.4