SAFE Function
The SAFE function retrieves an integer value for a specific device that when clocked into the JTAG chains will leave the pins of that device in a "safe" state.
The safe value will try to set all tristateable pins to be inputs, unless a pin needs to be driven to disable a device or if it is a pin that is specified to be constant.
This function can only be used inside a JTAG block. It should not be confused with the SAFE statement, which is used to return all the pins in the JTAG chains to their default, safe state.
The first example for JTAG scans demonstrates the use of the SAFE function.
Syntax
SAFE ( STRING deviceReference )Parameters
- deviceReference
-
A device reference in the form 'board.device'. The read-only built-in UNIQUE_DEVICE_REF contains this string for the current test device file. The board name is optional, but the device reference must uniquely identify the device; if there is any ambiguity, then the board name must be supplied.
Errors
An error can occur in the following circumstances:
- The deviceReference supplied does not contain a board name and matches more than one device. If the expression is constant, the error will occur at compile-time. Otherwise, the error will occur at run-time, when the function is run.
- The function is used outside a JTAG block.
See also
XJTAG v4.1.100