eZ80
®
CPU
User Manual
UM007714-0908 Manual Objectives
viii
Courier Typeface
Commands, code lines and fragments, bits, equations, hexadecimal addresses, and various
executable items are distinguished from general text by the use of the
Courier typeface.
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 a lowercase h and appear in the
Courier typeface.
•
Example: STAT is set to F8h.
Brackets
The square brackets, [ ], indicate a register or bus.
•
Example: for the register REG1[7:0], REG1 is an 8-bit register, REG1[7] is the msb,
and REG1[0] is the lsb.
Braces
The curly braces, { }, indicate a single register or bus created by concatenating some com-
bination of smaller registers, or buses.
•
Example: the 24-bit register {00h, REG1[7:0], REG2[7:0]} is composed of an 8-bit
hexadecimal value (
00h) and two 8-bit registers, REG1 and REG2. 00h is the MSB of
the 24-bit register, and REG2 is the LSB of the 24-bit register.
Parentheses
The parentheses, ( ), indicate an indirect register address lookup.
•
Example: (BC) is the memory location referenced by the address contained in the BC
register.
Parentheses/Bracket Combinations
The parentheses, ( ), indicate an indirect register address lookup and the square brackets, [
], indicate a register or bus.
•
Example: assume BC[15:0] contains the value 1234h. ({37h, BC[15:0]}) then refers
to the contents of the memory location at address
371234h.
Use of the Words Set and Clear
The words set and clear imply that a register bit or a condition contains a logical 1 and a
logical 0, respectively. When either of these terms is followed by a number, the word logi-
cal may not be included; however, it is implied.
To Next Page
Loading...
Need help?
General
