Chapter 5. Debug Support
5-11
Programming Model
Table 5-8. CSR Field Descriptions
Bit
Name
Description
31–28
BSTAT
Breakpoint status. Provides read-only status information concerning hardware breakpoints. BSTAT
is cleared by a TDR write or by a CSR read when either a level-2 breakpoint is triggered or a
level-1 breakpoint is triggered and the level-2 breakpoint is disabled.
0000 No breakpoints enabled
0001 Waiting for level-1 breakpoint
0010 Level-1 breakpoint triggered
0101 Waiting for level-2 breakpoint
0110 Level-2 breakpoint triggered
27
FOF
Fault-on-fault. If FOF is set, a catastrophic halt occurred and forced entry into BDM.
26
TRG
Hardware breakpoint trigger. If TRG is set, a hardware breakpoint halted the processor core and
forced entry into BDM. Reset and the debug GO command clear TRG.
25
HALT
Processor halt. If HALT is set, the processor executed a HALT and forced entry into BDM. Reset
and the debug GO command reset HALT.
24
BKPT
Breakpoint assert. If BKPT is set, BKPT was asserted, forcing the processor into BDM. Reset and
the debug GO command clears this bit.
23–20
HRL
Hardware revision level. Indicates the level of debug module functionality. An emulator could use
this information to identify the level of functionality supported.
0000 Initial debug functionality (Revision A)
0001 Revision B (this is the only valid value for the MCF5307)
19
—
Reserved, should be cleared.
18
BKD
Breakpoint disable. Used to disable the normal BKPT input functionality and to allow the assertion
of BKPT to generate a debug interrupt.
0 Normal operation
1 BKPT is edge-sensitive: a high-to-low edge on BKPT signals a debug interrupt to the processor.
The processor makes this interrupt request pending until the next sample point, when the
exception is initiated. In the ColdFire architecture, the interrupt sample point occurs once per
instruction. There is no support for nesting debug interrupts.
17
PCD
PSTCLK disable. Setting PCD disables generation of PSTCLK, PST and DDATA outputs and
forces them to remain quiescent.
16
IPW
Inhibit processor writes. Setting IPW inhibits processor-initiated writes to the debug module’s
programming model registers. IPW can be modied only by commands from the external
development system.
15
MAP
Force processor references in emulator mode.
0 All emulator-mode references are mapped into supervisor code and data spaces.
1 The processor maps all references while in emulator mode to a special address space, TT = 10,
TM = 101 or 110.
14
TRC
Force emulation mode on trace exception. If TRC = 1, the processor enters emulator mode when a
trace exception occurs.
13
EMU
Force emulation mode. If EMU = 1, the processor begins executing in emulator mode. See
12–11
DDC
Debug data control. Controls operand data capture for DDATA, which displays the number of bytes
dened by the operand reference size before the actual data; byte displays 8 bits, word displays 16
bits, and long displays 32 bits (one nibble at a time across multiple clock cycles). See
Table 5-2.00 No operand data is displayed.
01 Capture all write data.
10 Capture all read data.
11 Capture all read and write data.
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Freescale Semiconductor, Inc.
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