3 0001 - Register Operations

3 0001 - Register Operations🔗

package: ledum-bb68

opcode
(ldl i w)

w = bb68-gpr

i : (integer-in 0 255)
w : (integer-in 0 15)

mask: f000

value: 1000

Loads an 8-bit constant into the bottom 8 bits of the register "w", clearing its higher 8 bits to zero.

opcode
(ldh i a)

a = bb68-gpr

i : (integer-in 0 255)
a : (integer-in 0 15)

mask: f000

value: 3000

Loads an 8-bit constant into the higher 8 bits of the register "a", keeping its lower 8 bits unchanged.

macro opcode
(ldw r:bb68-gpr w:bb68-word)

Loads a 16-bit (word) constant into the register "r".

This is a macroinstruction composed of one LDH and one LDL instruction, each loading a half of the constant.

macro opcode
(ldd p:bb68-gprp l)

Loads 32-bit integer into the specified pair. The higher 16 bits go into the first register and the lower into the second.

private opcode
(ldr* w r)

w = bb68-gpr

r = bb68-gpr

w : (integer-in 0 15)
r : (integer-in 0 15)

mask: ff00

value: 2000

macro opcode
(ldr variant)

variant = dest:bb68-gpr src:bb68-gpr
| dest:bb68-gprp src:bb68-gprp

Copies/moves a value to a register or register pair dest from a given register (pair) src.

private opcode
(swap* α β)

α = bb68-gpr

β = bb68-gpr

α : (integer-in 0 15)
β : (integer-in 0 15)

mask: ff00

value: 2100

macro opcode
(swap variant)

variant = dest:bb68-gpr src:bb68-gpr
| dest:bb68-gprp src:bb68-gprp

Swaps values of a register or register pair dest with a given register (pair) src.