Zilog EZ80F916 - Manual (Page 8)

eZ80
®
CPU
User Manual
UM007715-0415 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.