Zilog Z80380 - Manual (Page 141)

5-107
Z380 ™
U SER ' S M ANUAL Z ILOG
DC-8297-03
MULTUW
MULTIPLY UNSIGNED (WORD)
MULTUW [HL,]src src = R, RX, IM, X
Operation: HL(31-0)
←
HL(15-0) x src(15-0)
The contents of the HL register are multiplied by the source operand and the product is
stored in the HL register. The contents of the source are unaffected. Both operands are
treated as unsigned, binary integers.
The initial contents of the HL register are overwritten by the result. The Carry flag is set to
indicate that the upper word of the HL register is required to represent the result; if the Carry
flag is cleared, the product can be correctly represented in 16 bits and the upper word of
the HL register merely holds zero.
Flags: S: Cleared
Z: Set if the result is zero; cleared otherwise
H: Unaffected
V: Cleared
N: Unaffected
C: Set if the product is greater than or equal to 65536; cleared otherwise
Addressing Execute
Mode Syntax Instruction Format Time Note
R: MULTUW [HL,]R 11101101 11001011 100110rr 11
RX: MULTUW [HL,]RX 11101101 11001011 1001110y 11
IM: MULTUW [HL,]nn 11101101 11001011 10011111 -n(low)- -n(high) 11
X: MULTUW [HL,](XY+d) 11y11101 11001011 ——d— 10011010 13+r I
Field Encodings: rr: 00 for BC, 01 for DE, 11 for HL
y:
0 for IX, 1 for IY