Casio CASSIOPEIA A-20 Service Manual & Parts List page 28

N o . Pin Name
58 A15
59 Vss
60 Vcc
61 A16
62 A17
63 A18
64 A19
65 A20
66 A21
67 A22
68 Vss
69 Vcc
70 A23
71 A24
72 A25
73 Vss (PLL)
74 CAP1
75 Vcc (PLL)
76 Vss
77 ONENB
78 Vcc
79 EXTAL
80 XTAL
81 TESTMDB
82 Vss
83 Vcc
84 MD2 / RXD0
85 MD1 / TXD0
86 MD0 / SCK0
87 BREQB
88 RESETB
89 NMI
90 IRL3B
91 RXD1
92 TXD1
93 SCK1
94 CTS1
95 RTS1
96 BACKB
97 IOIS16B
98 STATUS0
99 ONSTATUSB
100 Vss
101 CKIO
102 Vcc
103 MD4 / CE2BB
104 MD3 / CE2AB
105 ONB
106 RD / WRB
107 RDB
108 CS6B / CE1BB
109 CS5B / CE1AB
110 CS4B
111 CS3B
112 CS2B
113 CS1B
114 CS0B
115 Vss
116 Vcc
117 WE3B / ICIOWRB
118 WE2B / ICIORDB
I o / O u t Function
O Address bus
GND
+3.3V source
O Address bus
O Address bus
O Address bus
O Address bus
O Address bus
O Address bus
O Address bus
GND
+3.3V source
O Address bus
O Address bus
O Address bus
GND for PLL
O Capacitor connecting terminal for PLL
+3.3V source for PLL
GND
I ON Circuit enable signal
+3.3V source
I Oscillator in (10MHz)
O Oscillator out (10MHz)
I Test mode control
GND
+3.3V source
I Data input of serial port 0
I/O Data output of serial port 0
I/O Not used
I Bus request
I Reset signal from BGA288
I Non-maskable Interrupt request
I Interrupt request
I Data input of serial port 1
O Data output of serial port 1
I/O Clock of serial port 1
I Serial port 1 transmission permission
O Serial port 1 transmission request
O Bus access permission
I Write protect input
O
STATUS0 signal to BGA288
O V3ROM (+3.3V) ON/OFF control. H=ON
GND
I/O System clock I/O
+3.3V source
I/O PCMCIA CE2B signal
I/O PCMCIA CE2A signal
I On circuit start request
O Read/Write signal
O Read pulse
O Chip select-6 sigmal
O Chip select-5 sigmal
O Chip select-4 sigmal
O Not used
O Chip select-2 sigmal
O Chip select-1 sigmal
O Chip select-0 sigmal
GND
+3.3V source
O D31-D24 select signal / IO Write
O D23-D16 select signal / IO Read
— 25 —
To/From
BGA288
X2
X2
GND
BGA288
BGA288
BGA288
BGA288
BGA288
BGA288
IC5(RS232C),BGA288
IC5(RS232C),BGA288
BGA288
IC5(RS232C)
IC5(RS232C)
BGA288
BGA288
BGA288
BGA288,Power supply unit
BGA288
BGA288
BGA288
BGA288
BGA288,RAM,ROM
BGA288,ROM,LCD unit
BGA288
BGA288
BGA288,ROM Board
BGA288
ROM Board
ROM Board
BGA288
BGA288,ROM Board