HT49R50 Holtek Semiconductor Inc, HT49R50 Datasheet - Page 26

• Manufacturer Part Number: HT49R50
• Description: 8-Bit Microcontroller
• Manufacturer: Holtek Semiconductor Inc

LCD display memory
The HT49C50 provides an area of embedded
data memory for LCD display. This area is lo-
cated from 40H to 60H of the RAM at Bank 1.
Bank pointer (BP; located at 04H of the RAM) is
the switch between the RAM and the LCD dis-
play memory. When the BP is set as ²1², any
data written into 40H~60H will effect the LCD
display. When the BP is cleared to ²0², any data
written into 40H~60H means to access the gen-
eral purpose data memory. The LCD display
Display memory
26
memory can be read and written to only by indi-
rect addressing mode using MP1. When data is
written into the display data area, it is auto-
matically read by the LCD driver which then
generates the corresponding LCD driving sig-
nals. To turn the display on or off, a ²1² or a ²0²
is written to the corresponding bit of the display
memory, respectively. The figure illustrates the
mapping between the display memory and LCD
pattern for the HT49C50.
August 18, 1999
HT49C50