Z380 Datasheet, PDF (48/115 Pages) Zilog, Inc. – MICROPROCESSOR

ZILOG
INSTRUCTION SET (Continued)
Assignment of a value is indicated by the symbol “←”. For
example,
dst ← dst + src
indicates that the source data is added to the destination
data and the result is stored in the destination location. The
notation “dst (b)” is used to refer bit “b” of a given location,
“dst(m-n) is used to refer bit location m to n of the destina-
tion. For example,
HL(7) specifies bit 7 of the destination.
And
HL(23-16) specifies bit location 23 to
16 of the HL register.
Flags. The F register contains the following flags followed
by symbols.
S Sign flag
Z Zero flag
H Half carry flag
P/V Parity/Overflow flag
N Add/Subtract flag
C Carry Flag
¤ The flag is affected according to
the result of the operation.
• The flag is unchanged by the operation.
0 The flag is reset to 0 by operation.
1 The flag is set to 1 by operation.
V P/V flag affected according to the overflow
result of the operation.
P P/V flag affected according to the parity
result of the operation.
MICROPROCESSOR
Field Encoding
The convention for opcode binary format is shown in the
following Tables. For example, to get the opcode format
on the instruction LD (IX+12h), C; first find out the entry for
LD (XY+d),r. That entry has an opcode format of:
11 y11 101
01 110 r
← d →
At the bottom of each Table (between Table and Notes),
the binary format is the following:
r,r’ Reg
000 B
001 C
010 D
011 E
100 H
101 L
111 A
s Regs
y XY
000 B
0 IX
001 C
1 IY
010 D
011 E
100 IXU (x = 0),IYU(x = 1)
101 IXL (x = 0),IYL(x = 1)
111 A
To form the opcode first look for the y field value for the IX
register, which is 0. Then find r field value for the C register,
which is 001. Replace the y and r fields with the value from
the table; replace d value with the real number. The results
are:
76 543 210 Hex
11 011 101 DD
01 110 001 71
00 010 010 12
Condition Codes. The following symbols describe the
condition codes.
Z
Zero*
NZ Not Zero*
C
Carry*
NC No carry*
S
Sign
NS No Sign
NV No overflow
V
Overflow
PE Parity even
PO Parity odd
P
Positive
M
Minus
*Abbreviated set
PS010001-0301