User Manual

EHS6 Hardware Interface Overview
2.1 Application Interface
21
EHS6_HIO_v01.441 Page 15 of 38 2013-07-11
Confidential / Preliminary
When the EHS6 starts up, all GPIO lines (except GPIO1-GPIO3 and GPIO24) are set to high-
impedance state after initializing. Therefore, it is recommended to connect external pull-up or
pull-down resistors to those GPIO lines that are to be used as output. This is necessary to keep
these lines from floating or driving any external devices.
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
GPIO21 RXDDAI
GPIO22 TFSDAI
GPIO23 SCLK
GPIO24 RING0