Rev. 1.0, 02/00, page 695 of 1141
REC-CTL Duty Data Register 4 (RCDR4)
1
1
1
1
13
14
15
1
0
3
2
5
4
7
6
9
8
11
10
CMT41
W
12
—
—
—
—
—
—
—
—
0
CMT40
W
0
CMT43
W
0
CMT42
W
0
CMT45
W
0
CMT44
W
0
CMT47
W
0
CMT46
W
0
CMT49
W
0
CMT48
W
0
CMT4B
W
0
CMT4A
W
0
Bit :
Initial value :
R/W :
RCDR4 is a 12-bit write-only register that sets the timing of falling edge of the 0 pulse (short) of
REC-CTL in record or rewrite mode. In detection mode, it is used to detect the long/short pulse.
Only a word access is valid. If a byte access is attempted, correct operation is not guaranteed. If a
read is attempted, an undetermined value is read out. Bits 15 to 12 are reserved, and no write in
them is valid.
It is initialized to H'F000 by a reset, stand-by or module stop.
In record mode, set a value with the 57.5 percent duty cycle obtained from the set time T4
corresponding to the frequency
φ
s according to the following equation. See figure 26.60, REC-
CTL Signal Generation Timing.
RCDR4 = T4
×
φ
s/64
φ
is the servo clock frequency (= f
OSC
/2) in Hz, and T4 is the set timing (s).
At bit pattern detection, set the 0 pulse long/short threshold value at REV. See figure 26.56, Duty
Discriminator.
RCDR4 = H'FFF
−
(T4'
×
φ
s/80)
φ
s is the servo clock frequency (= f
OSC
/2) in Hz, and T4' is the 0 pulse long/short threshold value at
REV (s).