User's Manual

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EHS8 Hardware Interface Overview Page 18 of 43
2.1 Application Interface
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 EHS8_HIO_v02.770 2014-08-11
Confidential / Preliminary
2.1.5 Digital Audio Interface
EHS8‘s digital audio interface (DAI) can be used to connect audio devices capable of pulse
code modulation (PCM).
2.1.6 GPIO Interface
EHS8 offers a GPIO interface with 22 GPIO lines. The GPIO lines are shared with other
interfaces or functions: Fast shutdown (see
Section 2.1.13), status LED (see Section 2.1.12),
the PWM functionality (see Section 2.1.10), an pulse counter (see Section 2.1.11), ASC0 (see
Section 2.1.2), ASC1 (see Section 2.1.3), an SPI interface (see Section 2.1.8), an HSIC
interface (see
Section 2.1.9) and a PCM interface (see Section 2.1.10)
The following table shows the configuration variants for the GPIO pads. All variants are mutually
exclusive, i.e. a pad configured for instance as Status LED is locked for alternative usage. Table
2: GPIO lines and possible alternative assignment
GPIO Fast
Shutdown
Status
LED
PWM Pulse
Counter
ASC0 ASC1 SPI HSIC PCM
GPIO1 DTR0
GPIO2 DCD0
GPIO3 DSR0 SPI_CLK
GPIO4 FST_SHDN
GPIO5 Status
LED
GPIO6 PWM2
GPIO7 PWM1
GPIO8 COUNTER
GPIO11
GPIO12
GPIO13
GPIO14
GPIO15
GPIO16 RXD1 MOSI AP_WAKEUP
GPIO17 TXD1 MISO HOST_ACTIVE
GPIO18 RTS1 CP_WAKEUP
GPIO19 CTS1 SPI_CS SUSPEND
GPIO20 TXDDAI