User’s Manual 179
18.5 16-bit Load and Store 20-bit Address
Instruction clk A I S Z V C Operation
LDP (HL),HL 12 - - - - (HL) = L; (HL+1) = H.
(Adr[19:16] = A[3:0])
LDP (IX),HL 12 - - - - (IX) = L; (IX+1) = H.
(Adr[19:16] = A[3:0])
LDP (IY),HL 12 - - - - (IY) = L; (IY+1) = H.
(Adr[19:16] = A[3:0])
LDP HL,(HL) 10 - - - - L = (HL); H = (HL+1).
(Adr[19:16] = A[3:0])
LDP HL,(IX) 10 - - - - L = (IX); H = (IX+1).
(Adr[19:16] = A[3:0])
LDP HL,(IY) 10 - - - - L = (IY); H = (IY+1).
(Adr[19:16] = A[3:0])
LDP (mn),HL 15 - - - - (mn) = L; (mn+1) = H.
(Adr[19:16] = A[3:0])
LDP (mn),IX 15 - - - - (mn) = IXL; (mn+1) = IXH.
(Adr[19:16] = A[3:0])
LDP (mn),IY 15 - - - - (mn) = IYL; (mn+1) = IYH.
(Adr[19:16] = A[3:0])
LDP HL,(mn) 13 - - - - L = (mn); H = (mn+1).
(Adr[19:16] = A[3:0])
LDP IX,(mn) 13 - - - - IXL = (mn); IXH = (mn+1).
(Adr[19:16] = A[3:0])
LDP IY,(mn) 13 - - - - IYL = (mn); IYH = (mn+1).
(Adr[19:16] = A[3:0])
Note that the LDP instructions wrap around on a 64K page boundary. Since the LDP
instruc-
tion operates on two-byte values, the second byte will wrap around and be written at the
start of the page if you try to read or write across a page boundary. Thus, if you fetch or
store at address 0xn,0xFFFF, you will get the bytes located at 0xn,0xFFFF and
0xn,0x0000 instead of 0xn,0xFFFFand 0x(n+1),0x0000 as you
might expect. Therefore,
do
not
use LDP at any physical address ending in 0xFFFF.
18.6 Register to Register Moves
Instruction clk A I S Z V C Operation
LD r,g 2 r - - - - r = g; r,g any of B,
C, D, E, H, L, A
LD A,EIR 4 fr * * - - A = EIR
LD A,IIR 4 fr * * - - A = IIR
LD A,XPC 4 r - - - - A = MMU
LD EIR,A 4 - - - - EIR = A
LD IIR,A 4 - - - - IIR = A
LD XPC,A 4 - - - - XPC = A
LD HL,IX 4 r - - - - HL = IX
LD HL,IY 4 r - - - - HL = IY
LD IX,HL 4 - - - - IX = HL
LD IY,HL 4 - - - - IY = HL
LD SP,HL 2 - - - - SP = HL
LD SP,IX 4 - - - - SP = IX
LD SP,IY 4 - - - - SP = IY
LD dd',BC 4 - - - - dd' = BC (dd': 00-BC',
01-DE', 10-HL')
LD dd',DE 4 - - - - dd' = DE (dd': 00-BC',
01-DE', 10-HL')
To Next Page
Loading...
