User’s Manual
C166S V1 SubSystem
Central Processing Unit
User’s Manual
3-73
V 1.6, 2001-08
the 32-bit dividend before the division has started. After any division, MDL represents the
16-bit quotient.
Whenever this register is updated via software, the MDRIU flag in the MDC register is
set to 1. The MDRIU flag is cleared whenever the MDL register is read via software.
When a multiplication or division is interrupted before its completion and when a new
multiply or divide operation is to be performed within the ISR, the contents of MDL must
be saved along with the contents of registers MDH and MDC to avoid erroneous results.
The Multiply/Divide Control Register (MDC)
The bit-addressable 16-bit Multiply/Divide Control register is implicitly used by the CPU,
when it performs a multiplication or a division. It is used to store the required control
information for the corresponding multiply or divide operation. MDC is updated by
hardware during each single cycle of a multiply or divide instruction.
MDL
Multiply/Divide Low Word
SFR(FE0E
H
,07
H
)
Reset value: 0000
H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
MDL
rwh
Field
Bits
Type Description
MDL
[15:0]
rwh
Low part of MD
The low order 16 bits of the 32-bit multiply and
divide register MD.
MDC
Multiply/Divide Control
SFR(FF0E
H
,87
H
)
Reset value: 0000
H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
!!
!!
!!
MDR
IU
!!
!!
!!
!!
r
r
r
r
r
r
r
r
rwh
rwh
rwh
rwh
rwh
rwh
rwh
rwh
Содержание C166S V1 SubSystem
Страница 10: ...User s Manual C166S V1 SubSystem User s Manual I 6 V 1 6 2001 08...
Страница 16: ...User s Manual C166S V1 SubSystem Introduction User s Manual 1 6 V 1 6 2001 08...
Страница 126: ...User s Manual C166S V1 SubSystem Central Processing Unit User s Manual 3 96 V 1 6 2001 08...
Страница 178: ...User s Manual C166S V1 SubSystem Memory Organization User s Manual 4 52 V 1 6 2001 08...
Страница 206: ...User s Manual C166S V1 SubSystem Instruction Set User s Manual 5 28 V 1 6 2001 08...
Страница 306: ...User s Manual C166S V1 SubSystem Detailed Instruction Set User s Manual 6 100 V 1 6 2001 08...
Страница 362: ...User s Manual C166S V1 SubSystem The External Bus Interface User s Manual 8 40 V 1 6 2001 08...
Страница 452: ...User s Manual C166S V1 SubSystem General Purpose Timer Unit User s Manual 12 44 V 1 6 2001 08...
Страница 454: ...User s Manual C166S V1 SubSystem Instruction Index User s Manual 13 2 V 1 6 2001 08...
Страница 459: ......