GR716-DS-UM, May 2019, Version 1.29
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GR716
2.9
I/O switch matrix scenario examples
This chapter gives examples of how to configure the GR716 microcontroller and the I/O mux for fol-
lowing scenarios:
•
Sensor / Actuator Node using external SRAM to store data
•
Bus bridge using external SRAM to store data
•
Bus bridge booting from external serial ROM
This chapter presents examples of I/O mux configuration tables. The configuration tables e.g. table 22
should be interpreted as follow:
•
Each row represent an external I/O on the GR716 microcontroller device
•
The first column states the register and bits used to control the external I/O
•
The columns marked with a hexadecimal number states the value the function are selected with.
For reference see table 2.6.
•
The columns marked with <namn>.<index> are a combined user scenarios and gives the fixed
functions and pins for the scenario
•
Empty entries in columns marked with <namn>.<index> indicates that the user can assign any
valid function to the external pin according to table 2.6.
2.9.1
Scenario #1 - Sensor / Actuator Node
This chapter describes how to configure the I/O mux to node bus either via SPW, CAN or MIL-1553B
and at the same run internal or external ADC.
The following assumptions are made for the system:
•
All on-chip ADCs and DACs is used (or external ADC / DAC).
•
External RAM needs to be greater than 128KiB. (If the application needs less than that the inter-
nal on-chip memory should be used in order to utilize the pins on the device more efficiently).
For this example we assume 256KiB is needed.
•
Boot from external PROM is required.
In table 21 options of I/O configuration for using SPW, MIL-1553B and CAN as node bus are
depicted. Note that SpaceWire is connected on dedicated pins.
