NEC 78K0 Series User Manual page 479

CHAPTER 18 MULTIPLIER/DIVIDER (
(1) Remainder data register 0 (SDR0)
SDR0 is a 16-bit register that stores a remainder. This register stores 0 in the multiplication mode and the
remainder of an operation result in the division mode.
SDR0 can be read by an 8-bit or 16-bit memory manipulation instruction.
Reset signal generation sets SDR0 to 0000H.
Figure 18-2. Format of Remainder Data Register 0 (SDR0)
Address: FF60H, FF61H
Symbol
SDR0 SDR SDR SDR
015 014 013
Cautions 1. The value read from SDR0 during operation processing (while bit 7 (DMUE) of
multiplier/divider control register 0 (DMUC0) is 1) is not guaranteed.
2. SDR0 is reset when the operation is started (when DMUE is set to 1).
(2) Multiplication/division data register A0 (MDA0H, MDA0L)
MDA0 is a 32-bit register that sets a 16-bit multiplier A in the multiplication mode and a 32-bit dividend in the
division mode, and stores the 32-bit result of the operation (higher 16 bits: MDA0H, lower 16 bits: MDA0L).
Figure 18-3. Format of Multiplication/Division Data Register A0 (MDA0H, MDA0L)
Address: FF62H, FF63H, FF64H, FF65H
Symbol
FF65H (MDA0HH)
MDA0H MDA MDA MDA
031 030 029
Symbol FF63H (MDA0LH)
MDA0L MDA MDA MDA
015 014 013
Cautions 1. MDA0H is cleared to 0 when an operation is started in the multiplication mode (when
multiplier/divider control register 0 (DMUC0) is set to 81H).
2. Do not change the value of MDA0 during operation processing (while bit 7 (DMUE) of
multiplier/divider control register 0 (DMUC0) is 1).
executed, but the result is undefined.
3. The value read from MDA0 during operation processing (while DMUE is 1) is not guaranteed.
µ
PD78F0534, 78F0535, 78F0536, 78F0537, AND 78F0537D ONLY)
After reset: 0000H R
FF61H (SDR0H)
SDR SDR SDR SDR
012 011 010 009
After reset: 0000H, 0000H
MDA MDA MDA MDA MDA
028 027 026 025 024
MDA MDA MDA MDA MDA
012 011 010 009 008
Preliminary User's Manual U17260EJ3V1UD
FF60H (SDR0L)
SDR SDR SDR SDR SDR
008 007 006 005 004
R/W
FF64H (MDA0HL)
MDA MDA MDA MDA
023 022 021 020
FF62H (MDA0LL)
MDA MDA MDA MDA
007 006 005 004
Even in this case, the operation is
SDR SDR SDR SDR
003 002 001 000
MDA MDA MDA MDA
019 018 017 016
MDA MDA MDA MDA
003 002 001 000
479