UM10850
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User manual
Rev. 2.4 — 13 September 2016
410 of 464
NXP Semiconductors
UM10850
Chapter 29: LPC5410x Serial Wire Debug (SWD)
29.6.4.5.1
Command and Status Word register (CSW, offset 0x00) bit description
The CSW register contains command and status bits to facilitate communication between
the debugger and the device.
29.6.4.5.2
Request value register (REQUEST, offset 0x04) bit description
The REQUEST register is used by a debugger to send action requests to the device.
29.6.4.5.3
Return value register (RETURN, offset 0x08) bit description
The RETURN register provides any response from the device to the debugger.
Table 458. Register overview: ISP-AP (base address 0x1C04 0000)
Name
Access
Address
offset
Description
Reset value
Reference
CSW
R/W
0x00
Command and status word.
0
REQUEST R/W
0x04
Request from the debugger to the device.
0
RETURN
R/W
0x08
Return value from the device to the debugger.
0
ID
RO
0xFC
Identification register.
0x002A 0000
Table 459. Command and Status Word register (CSW, offset 0x00) bit description
Bit
Symbol
Description
Reset value
0
RESYNCH_REQ
The debugger sets this bit to requests a re-synchronization.
0
1
REQ_PENDING
A request is pending for the debugger: a value is waiting to be read from the
REQUEST register.
0
2
DBG_OR_ERR
When 1, a debug overrun has occurred: a REQUEST value has been
overwritten by the debugger before it was read by the device.
0
3
AHB_OR_ERR
When 1, an AHB overrun has occurred: a RETURN value has been overwritten
by the device before it was read by the debugger.
0
4
SOFT_RESET
This bit is write-only by the device and resets the ISP-AP.
0
5
CHIP_RESET_REQ
This write -only bit causes the device (but not the ISP-AP) to be reset.
0
31:6
-
Reserved
-
Table 460. Request value register (REQUEST, offset 0x04) bit description
Bit
Symbol
Description
Reset value
31:0
REQUEST
Request value. Reads as 0 when no new request is present. Cleared by the device. Can
be read back by the debugger in order to confirm communication.
0
Table 461. Return value register (RETURN, offset 0x08) bit description
Bit
Symbol
Description
Reset value
31:0
RETURN
Return value. This is any response from the device to the debugger. If no new data is
present, a debugger read will be stalled until new data is available.
0