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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
111
Intel XScale
®
Processor—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
3.6
Software Debug
This section describes the software debug and related features implemented in the
IXP45X/IXP46X network processors, namely:
• Debug modes, registers and exceptions
• A serial debug communication link via the JTAG interface
• A trace buffer
• A mechanism to load the instruction cache through JTAG
• Debug Handler SW requirements and suggestions
3.6.1
Definitions
Debug handler:
Debug handler is event handler that runs on the IXP45X/IXP46X
network processors, when a debug event occurs.
Debugger:
The debugger is software that runs on a host system outside of
the IXP45X/IXP46X network processors.
3.6.2
Debug Registers
CP15 Registers
CRn = 14; CRm = 8: instruction breakpoint register 0 (IBCR0)
CRn = 14; CRm = 9: instruction breakpoint register 1 (IBCR1)
CRn = 14; CRm = 0: data breakpoint register 0 (DBR0)
CRn = 14; CRm = 3: data breakpoint register 1 (DBR1)
CRn = 14; CRm = 4: data breakpoint control register (DBCON)
CP15 registers are accessible using MRC and MCR. CRn and CRm specify the register to
access. The opcode_1 and opcode_2 fields are not used and should be set to 0.
CP14 Registers
CRn = 8; CRm = 0: TX Register (TX)
CRn = 9; CRm = 0: RX Register (RX)
CRn = 10; CRm = 0: Debug Control and Status Register (DCSR)
CRn = 11; CRm = 0: Trace Buffer Register (TBREG)
CRn = 12; CRm = 0: Checkpoint Register 0 (CHKPT0)
CRn = 13; CRm = 0: Checkpoint Register 1 (CHKPT1)
CRn = 14; CRm = 0: TXRX Control Register (TXRXCTRL)
CP14 registers are accessible using MRC, MCR, LDC and STC (CDP to any CP14
registers will cause an undefined instruction trap). The CRn field specifies the number
of the register to access. The CRm, opcode_1, and opcode_2 fields are not used and
should be set to 0.
Access Checkpoint 0 Register (CHKPT0)
0b1100
MCR p14, 0, Rd, c12, c0, 0
MRC p14, 0, Rd, c12, c0, 0
Access Checkpoint 1 Register (CHKPT1)
0b1101
MCR p14, 0, Rd, c13, c0, 0
MRC p14, 0, Rd, c13, c0, 0
Access Transmit and Receive Debug Control
Register
0b1110
MCR p14, 0, Rd, c14, c0, 0
MRC p14, 0, Rd, c14, c0, 0
Table 34.
Accessing the Debug Registers (Sheet 2 of 2)
Function
CRn (Register #)
Instruction