3.3.8. A7TWrapCtrl

This block contains the test wrapper control multiplexor used during TIC testing of the core. A simplified diagram of the A7TWrapCtrl block is shown in Figure 3.5.

Figure 3.5. A7TWrapCtrl block system diagram

This block is only used during test mode when the wrapper is acting as an AHB slave, and drives the control inputs of the core with the TIC test data. It is separated from the main test block (A7TWrapTest) to allow for easier removal of the test wrapper.

When not in test mode the control inputs are driven to their default values (either HIGH or LOW), or are driven with wrapper inputs, such as the two interrupt lines and the JTAG pins. The AbortInt signal is generated in the A7WrapMaster block.

If the test wrapper is removed, then this multiplexor is optimized out during synthesis, and the outputs driven with their default values. It is also possible to remove this block if the test wrapper is not used. The default connections that the outputs must be tied to are shown in the A7TWrap HDL file.

BUSEN, DBE, and nENIN are all set to constant values, because they do not have to be controlled during normal system use, or during core TIC testing.

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