Nokia 8270 서비스 매뉴얼
NSD-5
3. System Module
PAMS Technical Documentation
Page 36
Nokia Corporation
Issue 1 05/02
User Interface
Functional Description
As shown in Figure 18, the MAD4 serial interface is used to control the serial LCD on the
user interface (UI) board and also to provide access to CCONT’s registers. The DataSelX
and DataClk are generated by MAD4 during both transmit and receive cycles. Each device
has its own chip select signal and must hold its data pin in a high-impedance state if its
chip select is not active. Data must be valid on the rising edge of DataClk during both the
transmit and receive cycles.
user interface (UI) board and also to provide access to CCONT’s registers. The DataSelX
and DataClk are generated by MAD4 during both transmit and receive cycles. Each device
has its own chip select signal and must hold its data pin in a high-impedance state if its
chip select is not active. Data must be valid on the rising edge of DataClk during both the
transmit and receive cycles.
Figure 18: UI system interface block diagram
The LCD driver requires 9-bit data from the MAD UIF block. The MSB indicates whether
the following 8-bit is data or command. When this bit is high, the following 8-bits are
display data; otherwise, when it is low, the following 8 bits are control data.
the following 8-bit is data or command. When this bit is high, the following 8-bits are
display data; otherwise, when it is low, the following 8 bits are control data.
The chip enable line also has to be modified to accommodate the interface. The new /CE
is from one of the GPIO pins (port 1, bit5).
is from one of the GPIO pins (port 1, bit5).
The user interface also monitors the PWR key and keyboard, as well as controlling the
LCD, backlight, microphone, earpiece, and alert (buzzer, VIBRA, LED).
LCD, backlight, microphone, earpiece, and alert (buzzer, VIBRA, LED).
Signal Definitions
Table 9 defines the electrical characteristics of the user interface signals. For details on
the interface signals, refer to the design specifications for MAD4 and UI.
the interface signals, refer to the design specifications for MAD4 and UI.
Signal
To
Signal Level (V)
High Low
Rising
time
Falling
time
Function
COL(4:0)
Keypad
> 2.24
< 0.62
NA
(a)
NA
(a)
drives the keyboard
colums
colums
ROW(5:0)
Keypad
> 2.24
< 0.62
NA
(a)
NA
(a)
sample keyboard rows
and drives the LCD
interface
and drives the LCD
interface
LCD-CS
LCD
> 2.24
< 0.62
10 ns
10 ns
chip select for the
LCD
LCD