Dividend Register L (Dvdntl); Operation; Bit/32 Bit Operations - Hitachi SH7095 Hardware User Manual

10.2.6

Dividend Register L (DVDNTL)

Bit:
Bit name:
Initial value:
R/W:
The dividend register L (DVDNTL) is a 32-bit read/write register in which the lower 32 bits of the
dividend used for 64 bit / 32 bit division operations are written. When a value is set in this register,
the 64 bit / 32 bit division operation begins. The value written in the DVDNT register for 32 bit/32
bit division is also set in this register. When a 64 bit/32 bit division operation is executed, the
value set as the dividend is lost and the quotient written here at the end of the operation. This
register is undefined after a power-on reset, manual reset, in the standby mode or in the module
standby mode.
10.3

Operation

10.3.1

64 Bit/32 Bit Operations

64 bit/32 bit operations work as follows:
1. The 32-bit divisor is set in the divisor register (DVSR).
2. The 64-bit dividend is set the dividend registers H and L (DVDNTH and DVDNTL). First set
the value in DVDNTH. When a value is written to DVDNTL, the 64 bit/32 bit operation
begins.
3. This unit finishes a single operation in 39 cycles (starting from the setting of the value in the
DVDNTL). When an overflow occurs, however, the operation ends in 6 cycles. See section
10.3.3, Handling of Overflows, for more information. Note that operation is signed.
4. After the operation, the 32-bit remainder is written to DVDNTH and the 32-bit quotient is
written to DVDNTL.
10.3.2 32 Bit/32 Bit Operations
32 bit/32 bit operations work as follows:
1. The 32-bit divisor is set in the divisor register (DVSR).
2. The 32-bit dividend is set the dividend register L (DVDNT) for 32-bit division. When a value
is written to DVDNT, the 32 bit/32 bit operation begins.
3. This unit finishes a single operation in 39 cycles (starting from the setting of the value in the
DVDNT). When an overflow occurs, however, the operation ends in 6 cycles. See section
10.3.3, Handling of Overflows, for more information. Note that the operation is signed.
282 Hitachi
31 30
— —
R/W R/W R/W
39 ...
...
— ... —
... R/W
3 2
— —
R/W R/W
1 0
—
R/W