Analog Devices ADSP-21364 system manual SPI Disable Switch SW8, Push Button Enable Switch SW9

ADSP-21364 EZ-KIT Lite Hardware Reference

SPI Disable Switch (SW8)

The SPI interface switch (SW8) disables the SPI chip select lines connected to the SPI flash memory and the AD1835A audio codec. The switch also disables the ADC_LRCLK and ADC_BCLK signals on the AD1835A device. The switch allows a customer to re-use the same pins on the SPI interface and on the expansion interface. The SW8 default is all positions ON unless any of the switch signals or the SPI interface signals are used on the expansion connector or via an EZ-Extender®.

Push Button Enable Switch (SW9)

The push button enable switch (SW9) disconnects the push buttons from the corresponding processor pins. This allows the signals to be used else- where on the board. Table 2-3shows the SW9 connections. By default, all of the switch positions are ON.

Table 2-3. Push Button Enable Switch (SW9) Connections

Switch Position	Push Button Reference Designator	Processor Pin
1	SW1	FLAG1
2	SW2	FLAG2
3	SW3	DAI_P19
4	SW4	DAI_P20

Position 6 of SW9 connects or disconnects the latch-enable pin of the LED to the logical OR of the ~WE and ~LED_CS signals. When position 6 is OFF, the latch-enable pin of the LED latch (U24) is pulled high, making the latch transparent. In this position, the value of the LEDs is directly con- nected to AD7–0.

ADSP-21364 EZ-KIT Lite Evaluation System Manual 2-11