Instruction Format; Flag States; Repeated Instruction Syntax; Shift Value - STMicroelectronics ST10 Series Programming Manual

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:
Instruction
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
IDX0
IDX0 +
IDX0 -
IDX0 + QX0
IDX0 - QX0
IDX0 + QX1
IDX0 - QX1
IDX1
IDX1 +
IDX1 -
IDX1 + QX0
IDX1 - QX0
IDX1 + QX1
IDX1 - QX1
GPR Offset
no-op
+
-
+ QR0
- QR0
Description
4-bit Encoding
1
h
2
h
3
h
4
h
5
h
6
h
7
h
9
h
A
h
B
h
C
h
D
h
E
h
F
h
3-bit Encoding
1
h
2
h
3
h
4
h
5
h
ST10 FAMILY PROGRAMMING MANUAL
Table 31 : IDX Addressing Mode Encoding and
GPR offset Encoding (continued)
Addressing Mode
+ QR1
- QR1

3.4.6 - Flag states

Flag
-
*

3.4.7 - Repeated instruction syntax

Repeatable instructions CoXXX are expressed as
follows when repeated
Repeat #data times CoXXX... or
5
Repeat MRW times CoXXX...
When MRW is invoked, the instruction is repeated
(MRW ) + 1 times, therefore the maximum num-
12-0
ber of times an instruction can be repeated is
13
8 192 (2 ) times.
#data is an integer value specifying the number
5
of times an instruction is repeated, #data
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.
4-bit Encoding
6
h
7
h
Description
Unchanged
Modified
must be
5
127/172