Renesas Hitachi H8S/2191, Hardware Manual

Page: 795 / 1065

Rev. 2.0, 11/00, page 768 of 1037
(2) PB-CTL Waveform Shaper in Slow Mode Operation
If bit 0 in the CTL control register (CTCR) is set to slow mode, slow reset function is
activated. In slow mode, if the falling edge is not detected within the specified time from
rising edge detection, PB-CTL is forcibly shut down (slow reset).
The time T
FS
(s) until the signal falls is the following interval after the rising edge of the
internal CTL signal is detected:
T
FS
= 16384
×
4
φ
s (
φ
s = f
OSC
/2)
When f
OSC
= 10 MHz, T
FS
= 13.1 ms.
Figure 28.54 shows the PB-CTL waveform in slow mode.
CTL waveform
Internal CTL signal
1 frame 1 frame 1 frame
Slow tracking delay Slow tracking delay Slow tracking delay
Accelera-
tion
Accelera-
tion
Accelera-
tion
Decelera-
tion
Decelera-
tion
Slow reset
Stop Stop
CTLP CTLP CTLP
Figure 28.54 PB-CTL Waveform in Slow Mode Operation