HT49CV5 Holtek Semiconductor, HT49CV5 Datasheet - Page 29

• Manufacturer Part Number: HT49CV5
• Description: A/D
• Manufacturer: Holtek Semiconductor

Rev. 1.20
VFD Display Control Register - VFDC
At power-on initial, the 11-grid, 11-segment & 1/16 pulse
width are set and the VFD display is disabled.
VFD clock source may come from the RTC or the sys-
tem clock/4 (f
Bit No.
2~0
7~5
3
4
VDM2~V
VGS2~
VGS0
Label
VFDE
DM0
SYS
VFDC (28H) Register
/4).
VFD Driver Output
Selects the VFD display mode
000= 4 grids, 16 segments
001= 5 grids, 16 segments
010= 6 grids, 16 segments
011= 7 grids, 15 segments
100= 8 grids, 14 segments
101= 9 grids, 13 segments
110= 10 grids, 12 segments
111= 11 grids, 11 segments
Unused bit, read as 0
Controls the VFD display
(1=enable; 0=disable)
Sets the VFD dimming quantity
000= set pulse width to 1/16.
001= set pulse width to 2/16.
010= set pulse width to 4/16.
011= set pulse width to 10/16.
100= set pulse width to 11/16.
101= set pulse width to 12/16.
110= set pulse width to 13/16.
111= set pulse width to 14/16.
Function
29
Low Voltage Reset
There is a low voltage reset circuit (LVR) implemented in
the microcontroller. This function can be enabled/dis-
abled by options.
If the supply voltage of the device is within the range
0.9V~V
tomatically reset the device internally.
The LVR includes the following specifications:
The relationship between V
Note:
The low voltage (0.9V~V
nal state for longer than 1ms. If the low voltage state
does not exceed 1ms, the LVR will ignore it and will
not perform a reset function.
The LVR uses an OR function with the external RES
signal to perform a chip reset.
LVR
V
operation at 4MHz system clock.
OPR
, such as changing a battery, the LVR will au-
is the voltage range for proper chip
HT49RV5/HT49CV5
LVR
DD
) has to remain in its origi-
and V
LVR
is shown below.
April 14, 2006