User`s manual

M9328MX1ADS - Rev 2 User’s Manual
20 Configuration and Operation MOTOROLA
Configuration and Operation
* Note: The voice output from the MX1 also connects to both
AUX1 channels causing them to be shorted.
Remove zero
ohm resistors R142 and R141 to break this connection.
For the details on the operation of DAC3550A, please refer to its
data sheet. The data sheet is available on the web:
http://www.micronas.com/
2.3.8 Keypads and IO Expander
The M9328MX1ADS is equipped with two Phillips PCF8575 I/O expanders.
One is for the keypad array and the other is for peripheral control. The keypad
array consist of a matrix of momentary push button switches mounted directly
to the ADS board. Figure 2-9 and Table 2-10 shows the interface of the I/O
expander to the keypads. The read slave address is 0x49. The PCF8575 can
be used to generated an interrupt whenever a key is pressed or released. The
interrupt signal is connected to the SIM_PD signal of the DBMX1 which
should be configured as GPIO, PB15. There is an additional push button
switch, S17, that is connected to the SPI_RDY signal of the DBMX1. That pin
should be configured as GPIO, PC13, to use it with S17. When any switch is
depressed it will cause a low (zero) to appear at the associated input pin. These
switches have no hardware debounce so that function must be handled by the
software.
Table 2-8 Audio Header JP4 Signal Descriptions
Pin Mnemonic Signal
1 AUX1R Auxiliary Input 1, right channel*
2,3 AGND Analog Ground
4 AUX1L Auxiliary Input 1, left channel*
Table 2-9 Audio Header JP5 Signal Descriptions
Pin Mnemonic Signal
1 AUX2R Auxiliary Input 2, right channel
2,3 AGND Analog Ground
4 AUX2L Auxiliary Input 2, left channel