UPD78F1502AGK-GAK-AX Datasheet, PDF (730/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 17 MULTIPLIER/DIVIDER
17.4 Operations of Multiplier/Divider
17.4.1 Multiplication operation
• Initial setting
<1> Set bit 7 (DIVMODE) of the multiplication/division control register (MDUC) to 0.
<2> Set the multiplicand to the multiplication/division data register A (L) (MDAL).
<3> Set the multiplier to the multiplication/division data register A (H) (MDAH).
(There is no preference in the order of executing steps <2> and <3>. Multiplication operation is automatically
started when the multiplier and multiplicand are set to MDAH and MDAL, respectively.)
• During operation processing
<4> Wait for at least one clock. The operation will end when one clock has been issued.
• Operation end
<5> Read the product (lower 16 bits) from the multiplication/division data register B (L) (MDBL).
<6> Read the product (higher 16 bits) from the multiplication/division data register B (H) (MDBH).
(There is no preference in the order of executing steps <5> and <6>.)
• Next operation
<7> To execute multiplication operation next, start from the “Initial setting” for multiplication operation.
<8> To execute division operation next, start from the “Initial setting” in 17.4.2 Division operation.
Remark Steps <1> to <7> correspond to <1> to <7> in Figure 17-6.
Figure 17-6. Timing Diagram of Multiplication Operation (0003H × 0002H)
Operation clock
DIVMODE "0" <1>
MDAH
MDAL
MDBH
Initial value = 0
Initial value = 0
Initial value = 0
0003H
FFFFH
0002H
FFFFH
<4>
<2> <3>
0006H
<5>, <6> <7>
1FFFEH
FFFE000H
R01UH0004EJ0501 Rev.5.01
714
Jun 20, 2011