Public Instructions - Analog Devices ADSP-BF506F Hardware Reference Manual

Boundary-Scan Architecture

Public Instructions

The following sections describe the public JTAG scan instructions.
EXTEST – Binary Code 00000
The instruction selects the boundary-scan register to be connected
EXTEST
between the
TDI
circuitry external to the device.
The instruction allows internal data to be driven to the boundary
EXTEST
outputs and external data to be captured on the boundary inputs.

To protect the internal logic when the boundary outputs are over-
driven or signals are received on the boundary inputs, make sure
that nothing else drives data on the processor's output pins.
SAMPLE/PRELOAD – Binary Code 10000
The
SAMPLE/PRELOAD
Boundary-Scan register to be connected between
instruction has no effect on internal logic.
The part of the instruction allows a snapshot of the inputs and
SAMPLE
outputs captured on the boundary-scan cells. Data is sampled on the ris-
ing edge of
TCK
The part of the instruction allows data to be loaded on the device
PRELOAD
pins and driven out on the board with the
loaded on the pins on the falling edge of
BYPASS – Binary Code 11111
The instruction selects the
BYPASS
and . The instruction has no effect on the internal logic. No data
TDO
inversion should occur between
B-6
and pins. This instruction allows testing of on-board
TDO
instruction performs two functions and selects the
.
TDI
ADSP-BF50x Blackfin Processor Hardware Reference
TDI
instruction. Data is pre-
EXTEST
.
TCK
register to be connected to
BYPASS
and .
TDO
and . The
TDO
TDI