Intel IXC1100, IXP42X 3.6.1 Definitions, 3.6.2 Debug Registers, 3.6.3 Debug Modes

Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
September 2006 DM
Order Number: 252480-006US 89
Intel XScale® Processor—Intel® IXP42X product line and IXC1100 control plane processors
• Debug Handler SW requirements and suggestions
3.6.1 Definitions
Debug handler: Debug handler is event handler that runs on IXP42X product line
and IXC1100 control plane processors, when a debug event
occurs.
Debugger: The debugger is software that runs on a host system outside of
IXP42X product line and IXC1100 control plane 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.
Software access to all debug registers must be done in privileged mode. User mode
access will generate an undefined instruction exception. Specifying registers which do
not exist has unpredictable results.
The TX and RX registers, certain bits in the TXRXCTRL register, and certain bits in the
DCSR can be accessed by a debugger through the JTAG interface.
3.6.3 Debug Modes
The IXP42X product line and IXC1100 control plane processors’ debug unit, when used
with a debugger application, allows software running on an IXP42X product line and
IXC1100 control plane processors’ target to be debugged. The debug unit allows the
debugger to stop program execution and re-direct execution to a debug handling
routine. Once program execution has stopped, the debugger can examine or modify
processor state, co-processor state, or memory. The debugger can then restart
execution of the application.
On IXP42X product line and IXC1100 control plane processors, one of two debug
modes can be entered:
•Halt mode
• Monitor mode