HT67F60 datasheet(205/242 Pages) HOLTEK

205 / 242 page

HT67F30/HT67F40/HT67F50/HT67F60

TinyPowerTM A/D Flash Type 8-Bit MCU with LCD & EEPROM

Rev. 1.50

204

March 06 , 2012

Rev. 1.50

205

March 06 , 2012

LVD Operation

The Low Voltage Detector function operates by comparing the power supply voltage, VDD, with a

pre-specified voltage level stored in the LVDC register. This has a range of between 2.0V and 4.4V.

When the power supply voltage, VDD, falls below this pre-determined value, the LVDO bit will be

set high indicating a low power supply voltage condition. The Low Voltage Detector function is

supplied by a reference voltage which will be automatically enabled. When the device is powered

down the low voltage detector will remain active if the LVDEN bit is high. After enabling the Low

Voltage Detector, a time delay tLVDS should be allowed for the circuitry to stabilise before reading the

LVDO bit. Note also that as the VDD voltage may rise and fall rather slowly, at the voltage nears that

of VLVD, there may be multiple bit LVDO transitions.

LVD Operation

VD D

V LV D

LV DE N

LV DO

t LV DS

The Low Voltage Detector also has its own interrupt which is contained within one of the Multi-

function interrupts, providing an alternative means of low voltage detection, in addition to polling

the LVDO bit. The interrupt will only be generated after a delay of tLVD after the LVDO bit has been

set high by a low voltage condition. When the device is powered down the Low Voltage Detector

will remain active if the LVDEN bit is high. In this case, the LVF interrupt request flag will be set,

causing an interrupt to be generated if VDD falls below the preset LVD voltage. This will cause the

device to wake-up from the SLEEP or IDLE Mode, however if the Low Voltage Detector wake up

function is not required then the LVF flag should be first set high before the device enters the SLEEP

or IDLE Mode.

When LVD function is enabled, it is recommenced to clear LVD flag first, and then enables interrupt

function to avoid mistake action.

LCD Driver

For large volume applications, which incorporate an LCD in their design, the use of a custom

display rather than a more expensive character based display reduces costs significantly. However,

the corresponding COM and SEG signals required, which vary in both amplitude and time, to drive

such a custom display require many special considerations for proper LCD operation to occur. These

devices all contain an LCD Driver function, which with their internal LCD signal generating

circuitry and various options, will automatically generate these time and amplitude varying signals

to provide a means of direct driving and easy interfacing to a range of custom LCDs.

All devices include a wide range of options to enable LCD displays of various types to be driven.

The table shows the range of options available across the device range.

HT67F60 Datasheet(PDF) 205 Page - Holtek Semiconductor Inc

HT67F60 Datasheet(HTML) 205 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL