2.5.2. ARMTAP_AccessDR_NoClk_W

Write a value to the data register (scan chain) of an ARM TAP controller.

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_AccessDR_W instead.

Syntax

#include “tapop.h”

extern TAPOp_ErrorARMTAP_AccessDR_NoClk_W(unsigned8 connectId, ScanData40 *TDIbits, unsigned8 TDIrev, unsigned8 len, unsigned8 WRoffset, ScanData40 *WRmask, unsigned8 deselect);

where:

connectId

Connection ID, as returned by TAPOp_OpenConnection.

TDIbits

A pointer to up to 40 bits of data to be written to the scan chain data register. This pointer must not be NULL.

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).

To write less than 40 bits of data using reversed mode you must set WRmask with bits set in the high-order end of the mask, not the low-order end.

len

The length of the selected data register (scan chain).

WRoffset

Offset of the selected data register (scan chain) where you start writing data. The rest of the scan chain is recirculated so that whatever data appears on TDO is put back into TDI during the scan.

To write less than 40 bits, specify zero here and use WRmask.

WRmask

A 40-bit mask that determines which bits are written to the data register (scan chain) during a scan:

  • if 1 then the bit is written

  • if 0 then the bit is recirculated, so that whatever comes out of the TDO pin is put back into TDI during the scan.

To write all 40 bits, you can set WRmask to NULL when using direct TAPOp calls. When defining macros, you must always specify the mask in full.

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_InBadTAPState

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

TAPOp_BadParameter

Failed because of one of the following:

  • TDIbits = NULL

  • len = 0

  • WRoffset >= len.

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 core is read from TDIbits and sent with the write mask and offset to the Multi-ICE interface unit. It is transferred to the scan chain that was selected by the last call to ARMTAP_AccessIR_nClks. The data written to the scan chain is not clocked into the core by this call.

The TAP controller must be in JTAG state Select-DR-Scan 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_AccessDR_NoClk_W 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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