STMicroelectronics ST10 Series, Programming Manual

Page: 129 / 174

ST10 FAMILY PROGRAMMING MANUAL
127/172
3.4.5 - Instruction format
The instruction format is the same as that of the
standard instruction set.
In addition, the following new symbols are used:
3.4.6 - Flag states
3.4.7 - Repeated instruction syntax
Repeatable instructions CoXXX are expressed as
follows when repeated
When MRW is invoked, the instruction is repeated
(MRW
12-0
) + 1 times, therefore the maximum num-
ber of times an instruction can be repeated is
8 192 (2
13
) times.
#data
5
is an integer value specifying the number
of times an instruction is repeated, #data
5
must be
less than 32.
Therefore, CoXXX can only be repeated less
than 32 times. When the MRW register is used in
the repeat instruction, the 5-bit repeat field is set
to 1.
3.4.8 - Shift value
The shifter authorizes only 8-bit left/right shifts.
Shift values must be between 0-8 (inclusive).
3.5 - MAC instruction descriptions
Each instruction is described in a standard format.
See “MAC instruction conventions” on page 126
for detailed information about the instruction con-
ventions. The MAC instruction set is divided into 5
functional groups:
– Multiply and Multiply-Accumulate Instructions
– 40-bit Arithmetic Instructions
– Shift Instructions
– Compare Instructions
– Transfer Instructions
The instructions are described in alphabetical
order.
Instruction Description
X 4-bit IDX addressing mode encoding.
(see following table)
:.qqq 3-bit GPR offset encoding for new GPR
indirect with offset encoding.
rrrr:r... 5-bit repeat field.
wwww:w... 5-bit CoReg address for CoSTORE
instructions.
ssss: 4-bit immediate shift value.
ssss:s... 5-bit immediate shift value.
Table 31 : IDX Addressing Mode Encoding and
GPR offset Encoding
Addressing Mode 4-bit Encoding
IDX0 1
h
IDX0 + 2
h
IDX0 - 3
h
IDX0 + QX0 4
h
IDX0 - QX0 5
h
IDX0 + QX1 6
h
IDX0 - QX1 7
h
IDX1 9
h
IDX1 + A
h
IDX1 - B
h
IDX1 + QX0 C
h
IDX1 - QX0 D
h
IDX1 + QX1 E
h
IDX1 - QX1 F
h
GPR Offset 3-bit Encoding
no-op 1
h
+ 2
h
- 3
h
+ QR0 4
h
- QR0 5
h
+ QR1 6
h
- QR1 7
h
Flag Description
- Unchanged
* Modified
Repeat #data
5
times CoXXX... or
Repeat MRW times CoXXX...
Table 31 : IDX Addressing Mode Encoding and
GPR offset Encoding (continued)
Addressing Mode 4-bit Encoding