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Rabbit 3000A Instruction
88
Rabbit 2000/3000 Microprocessor
Description
•
LDDSR
: While the data in BC does not equal 0, the memory location whose address is in DE is
loaded with the data at the address in HL. The data in BC and HL (but not DE) is then decre-
mented. This instruction then repeats until BC equals zero. If this instruction is prefixed by IOI
or IOE, the destination will be in the specified I/O space.
•
LDISR
: While the data in BC does not equal 0, the memory location whose address is in DE is
loaded with the data at the address in HL. The data in BC is then decremented and HL incre-
mented (the data in DE remains unchanged). This instruction then repeats until BC equals zero.
If this instruction is prefixed by IOI or IOE, the destination will be in the specified I/O space.
Add 1 clock for each iteration for the prefix if the prefix is IOI (internal I/O). If the prefix is IOE, add 2 clocks
plus the number of I/O wait states enabled. The V flag is cleared when BC transitions from 1 to 0. If the V
flag is not cleared another step is performed for the repeating versions of the instructions. Interrupts can occur
between different repeats, but not within an iteration. Return from the interrupt is to the first byte of the
instruction which is the I/O prefix byte if there is one.
These instructions are implemented in the Rabbit 3000A.
LDDSR
LDISR
Opcode
Instruction
Clocks
Operation
ED 98
LDDSR
6+7i (2,2,1,
(2,3,2)i,1)
(DE) = (HL);
BC = BC - 1; HL = HL - 1;
repeat while BC != 0
ED 90
LDISR
6+7i (2,2,1,
(2,3,2)i,1)
(DE) = (HL);
BC = BC; HL = HL + 1;
repeat while BC != 0
Flags
ALTD
I/O
S
Z
L/V
C
F
R
SP
S
D
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Summary of Contents for 2000
Page 2: ...ii Rabbit 2000 3000 Microprocessor...
Page 4: ...iv Rabbit 2000 Microprocessor...
Page 16: ...12 Rabbit 2000 3000 Microprocessor...
Page 164: ...160 Instruction Reference Manual...