ST20-C1 STMICROELECTRONICS [STMicroelectronics], ST20-C1 Datasheet - Page 6

• Manufacturer Part Number: ST20-C1
• Description: Instruction Set Reference Manual
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

2.1 Instruction listings
2
This chapter describes the notation used throughout this manual, including the
meaning of the instruction listings and the meanings and values of constants.
2.1
The instructions are listed in alphabetical order, one to a page. Descriptions are
presented in a standard format with the instruction mnemonic and full name of the
instruction at the top of the page, followed by these categories of information:
These categories are explained in more detail below, using the and instruction as an
example.
2.1.1
The header at the top of each page shows the instruction mnemonic and, on the right,
the full name of the instruction. For primary instructions the mnemonic is followed by
‘n’ to indicate the operand to the instruction; the same notation is used in the descrip-
tion to show how the operand is used. An explanation of the primary and secondary
instruction formats is given in section 3.4.
2.1.2
The code of the instruction is the value that would appear in memory to represent the
instruction.
For secondar y instructions the instruction ‘operation code’ is shown as the memory
code — the actual bytes, including any prefixes, which are stored in memory. The
value is given as a sequence of bytes in hexadecimal, decoded left to right. The codes
are stored in memory in ‘little-endian’ format, with the first b yte at the lowest address.
For example, the entry for the and instruction is:
This means that the hexadecimal byte value F9 would appear in memory for an and .
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Notation
Instruction listings
Code: the instruction code;
Description: a brief summary of the purpose and behavior of the instruction;
Definition: a more formal and complete description of the instruction, using
the notation described below in section 2.2;
Status Register: a list of errors and other changes to the Status Register
which can occur;
Comments: a list of other important features of the instruction;
See also: cross references are provided to other instructions with related func-
tions.
Instruction name
Code
Code: F9