Datasheet

 2016 Microchip Technology Inc. DS00002246A-page 43
KSZ8895MQX/RQX/FQX/MLX
2. Set the input signals PS[1:0] (pins 113 and 114, respectively) to “10” to set the serial configuration to SPI slave
mode.
3. Power up the board and assert a reset signal. After reset wait 100 µs, the start switch bit in Register 1 will be set
to ‘0’. Configure the desired settings in the KSZ8895MQX/RQX/FQX/MLX before setting the start switch to ‘1.'
4. Write configuration to registers using a typical SPI write data cycle as shown in Figure 3-11 or SPI multiple write
as shown in Figure 3-13. Note that data input on SPID is registered on the rising edge of SPIC.
5. Registers can be read and configuration can be verified with a typical SPI read data cycle as shown in Figure 3-
12 or a multiple read as shown in Figure 3-14. Note that read data is registered out of SPIQ on the falling edge
of SPIC.
6. After configuration is written and verified, write a ‘1’ to Register 1 bit 0 to begin KSZ8895MQX/RQX/FQX/MLX
switch operation.
7. All registers can be set on-the-fly after writing ‘1’ to Register 1 bit 0.
110 SCL SPI Clock
111 SPID/SDA Master Out Slave Input
109 SPIQ Master In Slave Output
FIGURE 3-11: SPI WRITE DATA CYCLE
FIGURE 3-12: SPI READ DATA CYCLE
TABLE 3-11: SPI CONNECTIONS
Pin Number Signal Name Microprocessor Signal Description