mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 194

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

S12X Debug (S12XDBGV3) Module
6.1.2
The comparators monitor the bus activity of the CPU12X. When a match occurs the control logic can
trigger the state sequencer to a new state. On a transition to the Final State, bus tracing is triggered and/or
a breakpoint can be generated.
Independent of comparator matches a transition to Final State with associated tracing and breakpoint can
be triggered by writing to the TRIG control bit.
The trace buffer is visible through a 2-byte window in the register address map and can be read out using
standard 16-bit word reads. Tracing is disabled when the MCU system is secured.
6.1.3
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Term
CPU
Tag
Four comparators (A, B, C, and D)
— Comparators A and C compare the full address bus and full 16-bit data bus
— Comparators A and C feature a data bus mask register
— Comparators B and D compare the full address bus only
— Each comparator can be configured to monitor CPU12X buses
— Each comparator features selection of read or write access cycles
— Comparators B and D allow selection of byte or word access cycles
— Comparisons can be used as triggers for the state sequencer
Three comparator modes
— Simple address/data comparator match mode
— Inside address range mode, Addmin ≤ Address ≤ Addmax
— Outside address range match mode, Address < Addmin or Address > Addmax
Two types of triggers
— Tagged — This triggers just before a specific instruction begins execution
— Force — This triggers on the first instruction boundary after a match occurs.
The following types of breakpoints
— CPU12X breakpoint entering BDM on breakpoint (BDM)
— CPU12X breakpoint executing SWI on breakpoint (SWI)
TRIG Immediate software trigger independent of comparators
Four trace modes
— Normal: change of flow (COF) PC information is stored (see
flow definition.
Overview
Features
CPU12X module
Tags can be attached to CPU opcodes as they enter the instruction pipe. If the tagged opcode reaches the
execution stage a tag hit occurs.
Table 6-2. Glossary Of Terms (continued)
S12XS Family Reference Manual, Rev. 1.10
Definition
Section
6.4.5.2.1) for change of
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