2.5.6. ARMTAP_AccessIR

Writes data to the TAP controller instruction register (IR).

Note

This function is deprecated. The first use by a connection causes a warning message to appear in the Multi-ICE server log window. It might not be supported in future releases. Use ARMTAP_AccessIR_nClks instead.

Syntax

#include “tapop.h”

extern TAPOp_ErrorARMTAP_AccessIR(unsigned8 connectId, unsigned16 TDIbits, unsigned8 TDIrev, unsigned8 deselect);

where:

connectId

Connection ID, as returned by TAPOp_OpenConnection.

TDIbits

Up to 16 bits of data to be written to the TAP controller instruction register. This must not be NULL and you cannot mask the value.

TDIrev

A flag determining the bit order of the data:

FALSE

Write LSB of TDIbits first (normal mode).

TRUE

Write MSB of TDIbits first (reversed mode).

deselect

If 0, the connection to this TAP controller remains selected. This excludes access to this TAP controller from other Multi-ICE server connections. Otherwise, the connection is deselected, giving other connections a chance to perform operations.

Return

The function returns:

TAPOp_NoError

No error.

TAPOp_UnableToSelect

Connection could not be made. You must try again later.

TAPOp_NoSuchConnection

The connectId was not recognized.

TAPOp_BadParameter

Failed because of one of the following:

  • TDIbits = NULL

  • len = 0

  • WRoffset >= len

  • nClks > 31.

TAPOp_InBadTAPState

The TAP controller was reset or is not in Select-DR-Scan.

TAPOp_RPC_Connection_Fail

The RPC connection was lost while processing this request.

Usage

The call attempts to select the connection. If this cannot be done (for example, because another TAP controller is being accessed), the call fails with a TAPOp_UnableToSelect error.

The data to write to the TAP controller is read from TDIbits and sent to the Multi-ICE interface unit. The IR length is part of the device configuration data. Refer to the TAP controller documentation for details on the IR instructions that are supported by your device.

The TAP does not go through Run-Test/Idle, so if an ARM data bus scan chain is selected no DCLK happens. The TAP controller must be in Select-DR-Scan state before the function is used, and is left in this state after the function has been performed.

If another connection on the same Multi-ICE server resets the TAP controllers by calling TAPOp_AnySequence_W, or TAPOp_AnySequence_RW, or TAPOp_TestResetSignal, all subsequent calls to ARMTAP_AccessIR are rejected with the error TAPOp_InBadTAPState until the reset is acknowledged. See TAPOp_AnySequence_W for more details.

See also

These TAPOp API functions provide similar or related functionality:

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