1.
2.
3.
1.
2.
7 GPIO Pins
There are sixteen GPIO pins available on the device. Several different functions are multiplexed to these
pins. Refer to section 2.15.6 of the datasheet for further information about GPIO pin configuration.
On the EVB all GPIO signals are connected to headers with pull up resistors. Through the headers,
signals may be injected to the device as inputs, or if configured as outputs monitored by external
equipment or connected to off-board logic. The GPIO VSC8489/VSC8490/VSC8491 Evaluation Board
User Guide Revision 1.0 June 2014 Vitesse Proprietary and Confidential Page 23 of 23 signals are also
connected to the FPGA for on board control if desired. Two GPIO configuration examples are provided.
To configure GPIO_6 as an interrupt (INTR) signal:
Write the Global:GPIO_6_Config_Status (1Ex0124) register as follows:
Bits 2:0 should be 010 to select the WIS Interrupt Output feature
Bits 7:5 should be 001 to setup Interrupt B from channel 1 as the source.
Bits 15:8 and 4:3 are don’t care bits here.
Global:GPIO_6_Config2 (1Ex0125) does not apply in this situation.
Write Channel 1’s WIS:EWIS_INTR_MASKA_2 (2xEE05) bit 0 to “1” to enable HIGH_BER_PEND to
trigger an interrupt. Bits 15:1 should be “0” as no other alarms should active an interrupt in this
case.
To configure GPIO_9 for Rx Alarm:
Write the Global:GPIO_9_Config_Status (1Ex012A) register as follows:
Bits 2:0 should be 001 to select PCS Activity LED output.
Bits 4:3 should be 00 to select Rx activity alarm for channel 0..
Bits 15:5 are don’t care bit here.
Write the PMA:VendorSpecificPMAControl2 (1xA100) register as follows:
Bit 7 should be 1 to select the blink time interval of 100 ms.
Bits 4:3 should be 00 to select Rx activity alarm for channel 0..
Bits 15:5 are don’t care bit here.
Please note that the GPIO pins share many different functions. Some functions are available on any
GPIO while some are only available on dedicated pins. Refer to the device datasheet when selecting
functions and GPIO pin assignments.
To Next Page
Loading...
