Table of Contents
Advertisement
INSTRUCTION SET REFERENCE
6.2.44
modtc
Mnemonic:
modtc
Format:
modtc
Description:
Reads and modifies TC register as specified with mask and src2. The src2
operand contains the value to be placed in the TC register; mask operand
specifies bits that may be changed. Only bits set in mask are modified. mask
must not enable modification of reserved bits. Once the TC register is
changed, its initial state is copied into dst.
The changed trace controls may take effect immediately or may be delayed.
When delayed, the changed trace controls may not take effect until after the
first non-branching instruction is fetched from memory or after four
non-branching instructions are executed.
For more information on the trace controls, refer to
and
CHAPTER 9, TRACING AND
Action:
mode_bits = 0x000000FE;
event_flags = 0X0F000000
temp = TC;
tempa = (event_flags & TC & mask) | (mode_bits & mask);
TC = (tempa & src2) | (TC & ~tempa);
dst = temp;
Faults:
STANDARD
Example:
modtc g12, g10, g2 # trace controls
Opcode:
modtc
See Also:
modac, modpc
6-80
Modify Trace Controls
mask,
src2,
reg/lit
reg/lit
DEBUGGING.
Refer to
# by g12; previous trace
# controls stored in g2.
654H
REG
dst
reg
CHAPTER 8, FAULTS
section 6.1.6, "Faults" (pg.
g10 masked
6-5).
Advertisement
Table of Contents
