NSC800 Datasheet, PDF (50/76 Pages) National Semiconductor (TI) – NSC800TM High-Performance Low-Power CMOS Microprocessor

12 10 Exchanges (Continued)
EXX
Exchange the contents of the BC DE and HL registers with
their corresponding alternate register
BC
B’C’
No flags affected
DE
D’E’
HL
H’L’
76543210
11011001
Timing
Addressing Mode
M cycles 1
T states 4
Implied
REGISTER MEMORY
EX (SP) ss
Exchange the two bytes at the top of the external memory
stack with the 16-bit register ss
(SP)
SS_L
No flags affected
(SP a 1)
SS_H
76543210
1 1 1 0 0 0 1 1 EX (SP) HL
Timing
M cycles 5
T states 19 (4 3 4 3 5)
Addressing Mode
Register Register Indirect
76 5 43210
1 1 N_X 1 1 1 0 1
EX (SP) IX (for N_X e 0)
EX (SP) IY (for N_X e 1)
11 1 00011
Timing
Addressing Mode
M cycles 6
T states 23 (4 4 3 4 3 5)
Register Register Indirect
12 11 Memory Block Moves and
Searches
SINGLE OPERATIONS
LDI
Move data from memory location (HL) to memory location
(DE) increment memory pointers and decrement byte
counter BC
w (DE)
(HL)
S NA
DE w DE a 1
Z NA
HL w HL a 1
H Reset
BC w BC b 1
P V Set if BC b1 ⁱ 0 other-
wise reset
N Reset
C NA
76543210
11101101
10100000
Timing
Addressing Mode
M cycles 4
T states 16 (4 4 3 5)
Register Indirect
LDD
Move data from memory location (HL) to memory location
(DE) and decrement memory pointer and byte counter BC
w (DE)
(HL)
S NA
DE w DE b 1
Z NA
HL w HL b 1
H Reset
BC w BC b 1
P V Set if BC b1 ⁱ 0 other-
wise reset
N Reset
C NA
76543210
11101101
10101000
Timing
Addressing Mode
M cycles 4
T states 16 (4 4 3 5)
Register Indirect
CPI
Compare data in memory location (HL) to the Accumulator
increment the memory pointer and decrement the byte
counter The Z flag is set if the comparison is equal
A b (HL)
HL w HL a 1
BC w BC b 1
Zw1
if A e (HL)
S Set if result of comparison sub-
tract is negative
Z Set if result of comparison is
zero
H Set according to borrow from
bit 4
P V Set if BC b 1 ⁱ 0 otherwise
reset
N Set
CNA
76543210
11101101
10100001
Timing
Addressing Mode
M cycles 4
T states 16 (4 4 3 5)
Register Indirect
CPD
Compare data in memory location (HL) to the Accumulator
and decrement the memory pointer and byte counter The Z
flag is set if the comparison is equal
A b (HL)
S Set if result is negative
HL w HL b 1
BC w BC b 1
Zw1
if A e (HL)
Z Set if result of comparison is
zero
H Set according to borrow from
bit 4
P V Set if BC b 1 ⁱ 0 otherwise
reset
N Set
CNA
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