SIC63616-(Rev. 1.0) NO. P146
3240-0412
4.12.6 I/O memory of integer multiplier
Table 4.12.6.1 shows the I/O addresses and the control bits for the integer multiplier.
Table 4.12.6.1 Control bits of integer multiplier
D3
D2
D1
D0
Name Init
∗
1
1
0
Address
Comment
Register
DRL3
DRL2
DRL1
DRL0
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF72H
DRL3
DRL2
DRL1
DRL0
DRL7
DRL6
DRL5
DRL4
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF73H
DRL7
DRL6
DRL5
DRL4
DRH3
DRH2
DRH1
DRH0
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF74H
DRH3
DRH2
DRH1
DRH0
DRH7
DRH6
DRH5
DRH4
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF75H
FF76H
NF
VF
ZF
CALMD
R
R/W
NF
VF
ZF
CALMD
0
0
0
0
Negative
Overflow
Zero
Run
Div.
Positive
No
No
Stop
Mult.
DRH7
DRH6
DRH5
DRH4
SR3
SR2
SR1
SR0
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF70H
SR3
SR2
SR1
SR0
SR7
SR6
SR5
SR4
–
∗
2
–
∗
2
–
∗
2
–
∗
2
R/W
FF71H
SR7
SR6
SR5
SR4
Low-order 8-bit destination register
(low-order 4 bits)
LSB
MSB
Low-order 8-bit destination register
(high-order 4 bits)
High-order 8-bit destination register
(low-order 4 bits)
LSB
MSB
High-order 8-bit destination register
(high-order 4 bits)
Negative flag
Overflow flag
Zero flag
Operation status (reading)
Calculation mode selection (writing)
Source register (low-order 4 bits)
LSB
MSB
Source register (high-order 4 bits)
FF16H
MDCKE SGCKE SWCKE RTCKE
R/W
MDCKE
SGCKE
SWCKE
RTCKE
0
0
0
0
Enable
Enable
Enable
Enable
Disable
Disable
Disable
Disable
Integer multiplier clock enable
Sound generator clock enable
Stopwatch timer clock enable
Clock timer clock enable
*1 Initial value at initial reset
*2 Not set in the circuit
*3 Constantly "0" when being read
MDCKE: Integer multiplier clock enable register (FF16H•D3)
Controls the operating clock supply to the integer multiplier.
When "1" is written: On
When "0" is written: Off
Reading: Valid
When "1" is written to MDCKE, the integer multiplier operating clock (CPU operating clock selected by
OSCC and CLKCHG) is supplied from the clock manager. If it is not necessary to run the integer multiplier,
stop the clock supply by setting MDCKE to "0" to reduce current consumption.
At initial reset, this register is set to "0".
SR0–SR7: Source register (FF70H, FF71H)
Used to set multipliers and divisors.
Set the low-order 4 bits of data to SR0–SR3 and the high-order 4 bits to SR4–SR7.
This register maintains the latest set value until the next writing, so it is not necessary to set data for each
operation if the same multiplier and divisor is used in a series of operations.
At initial reset, this register is undefined.