MLC510B Datasheet, PDF (20/31 Pages) Megawin Technology Co., Ltd – Single chip 8-bit micro-controller

Please set port 0 as output high before set it as input mode, if the internal pull-high effect needs to
be speeded up. If the I/O ports are not used in your application, please set them as input with
pull-high or output mode to avoid unnecessary power consumption.
When the internal pull-high register is enabled and the P0_CFG.3 is 0, the P0.0 ~ P0.3 is always
pulled high. When a. internal pull-high register is enabled, b. the P0_CFG.3 is 1 and c. LCD
function is enabled, the P0.0 ~ P0.3 is pulled high only for the last 30 microseconds of the
low-active period of each LCD COM.
1 COM period
P0
V0
floating
V0
V1
V1
COM0
V2
V2
VSS
P0 pull high enable
(about 30us)
Key Strobe function
Address
Name
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 _{Bit 0}
0252H STB_CTL
-
-
-
-
-
- STB_ SEG_
CLR MASK
0253H STB_COM -
-
-
-
- SC2 SC1 SC0
0254H P01_LTH P11 P10 P05 P04 P03 P02 P01 P00
STB_CTL (Key strobe control)
STB_CLR: setting this bit would enable STB_COM and P01_LTH update process
SEG_MASK = 0: LCD output the content of LCD RAM.
1: LCD output data ‘0’s
RW
-
-
-
When P0CFG.3 (or P0CFG.7 and P1CFG.3) is set to 1 and LCD function is turned on, the key
strobe function is enabled. When a P0.n (or P1.n) pin which key strobe function is enabled senses
logic low, the corresponding bit of P01_LTH would be set, and the current COM number, 0 ~ 4 (or 0
~ 3), would be latched to register STB_COM. The content of P01_LTH and STB_COM would not
be updated until the STB_CLR bit of STB_CTL register is set. Program could judge which key of the
key-matrix being pressed by decoding the STB_COM and P01_LTH registers. Note that when the
STB_CLR is set, the content of P01_LTH will be cleared to 00H.
20
MLC510B Technical Summary
MEGAWIN