Panasonic G600 Technical Manual page 24

BASEBAND OVERVIEW
6.2.1 Keypad
The Keypad has a 5 x 5 matrix allowing 25 keys to be scanned on a key being pressed, a keypad interrupt is
generated. To find which key is pressed the software must assert each column in turn and read which row is active.
Because of key bounce, the key press must then be confirmed twice at about 20mS intervals. Because the End
Key is also used to power on the phone it is allocated a complete row of the keyboard scan.
The Keyboard scanning is software controlled. Key pressed is indicated by an interrupt, but key release is
controlled by software.
Figure 2: Keypad Matrix
6.2.2 Subscriber Identity Module (SIM)
The SIM interface is designed for 5V SIMs, this requires the addition of a 5V step up regulator to provide the
Interface requirements for a 5V SIM.
The SIM outputs are open drain, and the inputs are 5V tolerant. To achieve the required rise time on the clock line
a transistor must be used to pull the clock high.
6.2.3 Time Processing Unit (TPU)
The TPU provides the GSM TDMA timing requirements for the system, external timing signals are provided by an
area of Microcode within the GEMINI chip.
Issue 1
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KEYBD (0-9)
0 1
PWR/END
PWR_KEY
1
S417
S416
4
S411 S412
7
S406 S407
*
S401 S402
GEMINI Pin Description
65 VEGA BENA
66 VEGA BCAL
67 VEGA BULON
68 VEGA BDLON
69 RF signal IFLOSEL
70 RF signal LO_EN
118 RF signal RXON1
119 RF signal RXON2
58 Used as nTSPEN (0) (VEGA SELECT)
2 3
KEYPAD
D422
2 3 SND
S418 S419
V
5 6
S413 S414
8 9
S408 S409
0 # SOFTKEY
S403 S404
Section 6
6 - 2
4
5
PHONE
BOOK
S420 6
V
S415 7
8
S410
CLR
S405 9
600-0602
MCUK980101G8
Technical Guide