BH67F2260 Datasheet, PDF (210/253 Pages) Holtek Semiconductor Inc – R-Sensor Blood Pressure Meter Flash MCU with LCD

BH67F2260/BH67F2270
R-Sensor Blood Pressure Meter Flash MCU with LCD
2DH of the RAM at Sector 4 of the Data Memory for BH67F2270. If using the indirect addressing
to access the Display Memory therefore requires first that Sector 4 is selected by writing a value of
04H to MP1H or MP2H. After this, the memory can then be accessed by using indirect addressing
through the use of MP1L or MP2L. With Sector 4 selected, then using MP1L/MP2L to read or
write to the memory area, from 00H to 2DH, will result in operations to the LCD memory. Directly
addressing the Display Memory is not applicable and will result in a data access to the Sector 0
General Purpose Data Memory.
The LCD display memory can be read and written to only by indirect addressing mode using MP1L/
MP1H and MP2L/MP2H. When data is written into the display data area, it is automatically read
by the LCD driver which then generates the corresponding LCD driving signals. To turn the display
on or off, a “1” or a “0” is written to the corresponding bit of the display memory, respectively. The
figure illustrates the mapping between the display memory and LCD pattern for these devices.
The unimplemented LCD RAM bits cannot be used as general purpose RAM for application. For
example, if the LCD duty is selected as 1/4 duty (4COM), the COM bit 4~7 will be read as 0 only.
b7 b6 b5 b4 b3 b2 b1 b0
400H
SEG 0
401H
SEG 1
402H
SEG 2
403H
SEG 3
41CH
41DH
41EH
41FH
SEG 28
SEG 29
SEG 30
SEG 31
32 SEG x 8 COM
LCD Memory Map – BH67F2260
Rev. 1.00
210
March 15, 2017