UM012811-0904
Manual
Objectives
eZ8 CPU
User Manual
ix
Where the use of the font is not indicated, as in the Index, the name of the entity is pre-
sented in upper case.
•
Example: FLAGS[1] is
smrf
.
Hexadecimal Values
Hexadecimal values are designated by uppercase
H
and appear in the
Courier
typeface.
•
Example: R1 is set to
F8H.
Brackets
The square brackets, [ ], indicate a register or bus.
•
Example: for the register R1[7:0], R1 is an 8-bit register, R1[7] is the most significant
bit, and R1[0] is the least significant bit.
Braces
The curly braces, { }, indicate a single register or bus created by concatenating some com-
bination of smaller registers, buses, or individual bits.
•
Example: the 12-bit register address {
0H
, RP[7:4], R1[3:0]} is composed of a 4-bit
hexadecimal value (
0H
) and two 4-bit register values taken from the Register Pointer
(RP) and Working Register R1.
0H
is the most significant nibble (4-bit value) of the
12-bit register, and R1[3:0] is the least significant nibble of the 12-bit register.
Parentheses
The parentheses, ( ), indicate an indirect register address lookup.
•
Example: (R1) is the memory location referenced by the address contained in the
Working Register R1.
Parentheses/Bracket Combinations
The parentheses, ( ), indicate an indirect register address lookup and the square brackets,
[ ], indicate a register or bus.
•
Example:
assume PC[15:0] contains the value
1234h
. (PC[15:0]) then refers
to the
contents of the memory location at address
1234h
.
Use of the Words Set, Reset and Clear
The word
set
implies that a register bit or a condition contains a logical 1. The word re
set
or
clear
implies that a register bit or a condition contains a logical 0. When either of these
terms is followed by a number, the word
logical
may not be included; however, it is
implied.
