Rev. 1.0, 02/00, page 624 of 1141
Bits 7 and 6
Clock Source Selection Bits (DFCS1, DFCS0): DFCS1 and DFCS0 select the
clock to be supplied to the counter. (
φ
s = fosc/2)
Bit 7
Bit 6
DFCS1
DFCS0
Description
0
φ
s
(Initial value)
0
1
φ
s/2
0
φ
s/4
1
1
φ
s/8
Bit 5
Counter Overflow Flag (DFOVF): DFOVF flag indicates the overflow of the 16-bit
timer counter. It is cleared by writing 0. Write 0 after reading 1. Setting has the highest priority
in this flag. If a flag set and 0 write occurs simultaneously, the latter is invalid.
Bit 5
DFOVF
Description
0
Normal state.
(Initial value)
1
Indicates that overflow has occurred in the counter.
Bit 4
Error Data Limit Function Selection Bit (DFRFON): Enables the error data limit
function. (Limit values are the values set in the lock range data registers (DFRUDR and
DFRLDR)).
Bit 4
DFRFON
Description
0
Disables limit function.
(Initial value)
1
Enables limit function.
Bit 3
Drum Lock Flag (DF-R/UNR): Sets a flag if an underflow occurred in the drum lock
counter.
Bit 3
DF-R/UNR
Description
0
Indicates that the drum speed system is not locked.
(Initial value)
1
Indicates that the drum speed system is locked.