HT56R67 datasheet(29/104 Pages) HOLTEK

29 / 104 page

HT56R67/HT56R668/HT56C668/HT56R678/HT56C678/HT56R688

Rev. 1.20

March 4, 2010

Display Memory

An area of Data Memory is especially reserved for use

for the LCD/LED display data. This data area is known

as the Display Memory. Any data written here will be au-

tomatically read by the internal display driver circuits,

which will in turn automatically generate the necessary

LCD or LED driving signals. Therefore any data written

into this Memory will be immediately reflected into the

actual display connected to the microcontroller.

As the Display Memory addresses overlap those of the

General Purpose Data Memory, it s stored in its own in-

dependent Bank 1 area. The Data Memory Bank to be

used is chosen by using the Bank Pointer, which is a

special function register in the Data Memory, with the

name, BP. To access the Display Memory therefore re-

quires first that Bank 1 is selected by writing a value of

01H to the BP register. After this, the memory can then

be accessed by using indirect addressing through the

use of Memory Pointer MP1. With Bank 1 selected, then

using MP1 to read or write to the memory area, starting

with address 40H, will result in operations to the Display

Memory. Directly addressing the Display Memory is not

applicable and will result in a data access to the Bank 0

General Purpose Data Memory.

The accompanying Display Memory Map diagrams

shows how the internal Display Memory is mapped to

the Segments and Commons of the display for the larg-

est device, which is the HT56R678/HT56C678/

HT56R688. Display Memory Maps for devices with

smaller memory capacities can be extrapolated from

these diagrams.

The accompanying waveform diagrams show the gen-

erated waveforms for a range of duty and bias types.

The huge number of permutations of available for the

LCD and LED waveform types does not permit all types

to be depicted.

4 0 H

8 7 H

b 7

b 6

b 5

b 4

b 3

b 2

b 1

b 0

4 1 H

8 6 H

S E G 0

S E G 7 1

S E G 1

S E G 7 0

HT56R678/HT56C678/HT56R688

Memory Map

- 72´8

4 0 H

7 F H

b 7

b 6

b 5

b 4

b 3

b 2

b 1

b 0

4 1 H

b 7

b 6

b 5

b 4

b 3

b 2

b 1

b 0

S E G 0

S E G 6 3

S E G 1

S E G 6 2

7 E H

S E G 0

S E G 6 3

S E G 1

S E G 6 2

8 0 H

8 1 H

B F H

B E H

HT56R678/HT56C678/HT56R688 Memory Map

- 64´16

HT56R67 Datasheet(PDF) 29 Page - Holtek Semiconductor Inc

HT56R67 Datasheet(HTML) 29 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