ISM480 GPS State of Pins after Reset

After a reset (internally pulled up, power up generates the first reset) and before the first time ON_OFF.

Pin          Description                         Reset State

1              CTS/SPI_CL/GPIO6          Pad Enabled, Low, Weak Pull-down Enabled

2              RX/MOSI/SDA                   Pad Enabled, High

3              TX/MISO/SCL                     Pad Enabled, High

4              RTS/SPI_CS/GPIO7          Pad Enabled, High, Weak Pull-up Enabled

5              Reset                                    Pad Enabled, High, Pull-up Enabled

6              Wakeup                               Pad Enabled, Low

7              On_OFF                               Pad Enabled, Low

8              Flash Enable                       Pad Enabled, Low

9              GPIO3                                   Pad Enabled, High

When  the ON_OFF is pulsed for the first time the levels of  GPIO6 and GPIO7 are read to configure the host interface.

The reset is looked at by SiRF/CSR as an “External emergency override of internal POR”, so it is recommend to
control the GPS through the use of the ON_OFF pin

Posted in: GPS, Sirf IV