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Debug Port
c. The Sticky column indicates whether any Sticky flag is set in the DP CTRL/STAT register, see The Control/Status Register,
CTRL/STAT on page 12-53.
d. The state of the AP when the current scan reaches the Capture-DR state, or the response from the AP at that time.
e. UNP = Unpredictable.
f. If the Overrun Detect flag is set then this access/response sequence causes the Sticky Overrun flag to be set. See The
Control/Status Register, CTRL/STAT on page 12-53.
g. If Pushed Verify or Pushed Compare is enabled, the behavior is Unpredictable. Otherwise, returns the value of the AP Register
addressed on the previous scan.
h. If Pushed Verify or Pushed Compare is enabled, the previous transaction performed the required pushed operation, which
might have set the Sticky Compare flag, see Pushed compare and pushed verify operations on page 12-44. Otherwise, the data
captured at the previous scan has been written to the AP register requested.
JTAG access type
Read
Write
Read or Write
Read or Write
12-18
Host response summary
The ACK column, for the Current scan, at Capture-DR state section of Table 12-5 on
page 12-17, shows the responses the host might receive after initiating a DPACC or
APACC access.
ACK from target
Suggested host action in response to ACK
OK/FAULT
Capture read data.
OK/FAULT
No more action required.
WAIT
Repeat the same access until either an OK/FAULT ACK is received or the
wait timeout is reached.
If necessary, use the DAP ABORT register to enable access to the AP.
Invalid ACK
Assume a target or line error has occurred and treat as a fatal error.
The JTAG-DP Abort Register (ABORT)
Purpose
Access the DP Abort Register, to force a DAP abort.
This is the JTAG-DP implementation of the Abort Register, see The Abort
Register, ABORT on page 12-49.
Length
35 bits.
Operating mode
When the ABORT instruction is the current instruction in the IR, the
serial path between TDI and TDO is connected to a 35-bit scan chain that
is used to access the Abort Register.
Copyright © 2005, 2006 ARM Limited. All rights reserved.
Table 12-6 Summary of JTAG host responses
ARM DDI 0337B
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