9 Control/Status Register, CTRLSTAT

The Control/Status register provides control of the DP and status information about the DP.

The CTRLSTAT register characteristics are:

Attributes
Offset

0x0004

Type

Read-write

Reset

0x00000000

Width

32

The following figure shows the bit assignments.

Figure 9-6 CTRLSTAT register bit assignments
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The following table shows the bit assignments.

Table 9-7 CTRLSTAT register bit assignments

Bits Reset value Name Function
[31] Unknown CSYSPWRUPACK

System powerup acknowledge. Status of CSYSPWRUPACK interface signal.

[30] 0b0 CSYSPWRUPREQ

System powerup request. This bit controls the CSYSPWRUPREQ signal on the interface.

[29] Unknown CDBGPWRUPACK

Debug powerup acknowledge. Status of CDBGPWRUPACK interface signal.

[28] 0b0 CDBGPWRUPREQ

Debug powerup request. This bit controls the CDBGPRWUPREQ signal on the interface.

[27] Unknown CDBGRSTACK

Debug reset acknowledge. Indicates the status of the CDBGRSTACK signal on the interface.

[26] 0b0 CDBGRSTREQ

Debug reset request. This bit controls the CDBGRSTREQ signal on interface.

[24] 0b0 ERRMODE

Error Mode.

0

Errors on AP transactions set CTRLSTAT.STICKYERR.

1

Errors on AP transactions do not set CTRLSTAT.STICKYERR.

[7] 0b0 WDATAERR

This bit is DATA LINK DEFINED, such that on a JTAG-DP this bit is reserved, RES0, and on an SW-DP this bit is RO. This bit is set to 1 if a Write Data Error occurs. This happens if there is a parity or framing error on the data phase of a write, or a write that has been accepted by the DP is then discarded without being submitted to the AP. On an SW-DP, this bit is cleared to 0 by writing 1 to the ABORT.WDERRCLR bit.

[6] 0b0 READOK

This flag always indicates the response to the last AP read access. This bit is DATA LINK DEFINED. On JTAG-DP, the bit is reserved, RES0, and on SW-DP, access is RO. If the response to the previous AP read or RDBUFF read was OK, then the bit is set to 1. If the response was not OK, then it is cleared to 0.

[5] 0b0 STICKYERR

If an error is returned by an AP transaction, and CTRLSTAT.ERRMODE is b0, then this bit is set to 1. The behavior on writing is DATA LINK DEFINED: On a JTAG-DP, access is R/W1C. On a SW-DP, access is RO/WI.

Clearing this bit to 0 is also DATA LINK DEFINED: On a JTAG-DP, the bit is cleared by writing 1 to this bit, or by writing 1 to the ABORT.STKERRCLR field. On SW-DP, the bit is cleared by writing 1 to the ABORT.STKERRCLR field.

[1] 0b0 STICKYORUN

If overrun detection is enabled, this bit is set to 1 when an overrun occurs. The behavior on writing is DATA LINK DEFINED: on a JTAG-DP, access is R/W1C. On a SW-DP, access is RO/WI.

Clearing this bit to 0 is also DATA LINK DEFINED: On a JTAG-DP, the bit is cleared by writing 1 to this bit, or by writing 1 to the ABORT.ORUNERRCLR field. On SW-DP, the bit is cleared by writing 1 to the ABORT.ORUNERRCLR field.

[0] 0b0 ORUNDETECT

This bit is set to 1 to enable overrun detection.

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