tm1300 NXP Semiconductors, tm1300 Datasheet - Page 56

• Manufacturer Part Number: tm1300
• Description: Tm-1300 Media Processor
• Manufacturer: NXP Semiconductors

TM1300 Data Book
3.2.3
Compute operations are register-to-register operations.
The specified operation is performed on one or two
source registers and the result is written to the destina-
tion register.
Immediate Operations. Immediate operations load an
immediate constant (specified in the opcode) and pro-
duce a result in the destination register.
Floating-Point Compute Operations. Floating-point
compute operations are register-to-register operations.
The specified operation is performed on one or two
source registers and the result is written to the destina-
tion register. Unless otherwise mentioned all floating
point operations observe the rounding mode bits defined
in the PCSW register. All floating-point operations not
ending in ‘flags’ update the PCSW exception flags. All
operations ending in ‘flags’ compute the exception flags
as if the operation were executed and return the flag val-
ues (in the same format as in the PCSW); the exception
flags in the PCSW itself remain unchanged.
Multimedia Operations. These special compute opera-
tions are like normal compute operations, but the speci-
fied operations are not usually found in general purpose
CPUs. These operations provide special support for mul-
timedia applications.
3.2.4
Special register operations operate on the special regis-
ters: PCSW, DPC, SPC and CCCOUNT.
3-6
Figure 3-3. TM1300 issue slots, functional units, and latency.
Compute Operations
Special-Register Operations
issue slot 1
SHIFTER
DSPALU
CONST
FALU
ALU
PRODUCT SPECIFICATION
recovery 16)
(latency 17,
issue slot 2
SHIFTER
DSPMUL
BRANCH
FTOUGH
CONST
IFMUL
ALU
issue slot 3
BRANCH
DSPMUL
DSPALU
FCOMP
CONST
IFMUL
ALU
3.2.5
Control-flow operations change the value of the program
counter. Conditional jumps test the value in a register
and, based on this value, change the program counter to
the address contained in a second register or continue
execution with the next instruction. Unconditional jumps
always change the program counter to the specified im-
mediate address.
Control-flow operations can be interruptible or non-inter-
ruptible. Execution of an interruptible jump is the only oc-
casion where TM1300 allows special event handling to
take place (see
3.3
The TM1300 VLIW CPU allows issue of 5 operations in
each clock cycle according to a set of specific issue
rules. The issue rules impose issue time constraints and
a result writeback constraint. Any set of operations that
meets all constraints constitutes a legal TM1300 instruc-
tion. A more extensive description and a few special case
issue rules and limitations can be found in the Philips Tri-
Media SDE documentation.
Issue time constraints:
• an operation implies a need for a functional unit type
• each operation requires an issue slot that has an
(as documented in
tions for
instance of the appropriate functional unit type
attached
TM1300 INSTRUCTION ISSUE RULES
Control-Flow Operations
issue slot 4
BRANCH
TM1300.”)
CONST
DMEM
FALU
ALU
Section 3.5, “Special Event
Appendix A, “DSPCPU Opera-
Philips Semiconductors
DMEMSPEC
issue slot 5
CONST
DMEM
ALU
Handling”).