Sharp UP-3301 Service Manual page 62

10. WAIT control
The wait control function is built in the MPCA8 and is used to provide an interface with low-speed devices.
10-1. Block diagram
The block diagram of the wait control function is shown.
RAS
DECODER
ADDRESS
ROS
IO
X3
WAIT
ENABLE
REGS.
DATA
<00FF8Fh>
WAIT PULSE
GENERATOR
In the figure, the decoder, wait enabling register, AND-OR sections are
the same as those in the MPCA6 or 7, but other components are newly
incorporated in the MPCA7.
EXWAITZ and WAITZ are external wait signals which are to be read
inside the MPCA8 and output to the WAITZ. The EXWAITZ is a gen-
eral-purpose wait request terminal, and WAITZ is the wait request sig-
nal from the VGA controller.
11. CKDC9
The UP-3301 performs the following controls, using the CKDC9.
• Customer display
• Clock
• Buzzer
• System reset
11-1. Interface
CKDC9 is connected through the MPCA8.
HTS
TXD2(P87)
TXD1 HTS1
SCK
SCK1
SCK2(P83) SCL1
STH
STH1
RXD2(P84)
RXD1
H8/510
IRQ0 IRQ0
RESET
RES
MPCA8
STOP
(P57) FT12
RESET
Fig. 11
ENABLE
1WAIT
2WAIT
3WAIT
HTS
SCK
STH Standard
CKDC9
INT1 KRQ
SHEN
RESET
SRES
STOP
UP-3301US CIRCUIT DESCRIPTION
S
E
L
E
C
T
O
R
ADDRESS
WAIT
CONTROL
REGS.
DATA
<00FF8Dh>
Fig. 10
12. Option RAM interface
12-1. Interface
The expanded RAM connector terminals are shown in the table.
The 72 pin S.O. DIMM is used for the connector.
Extension RAM connector terminals
Signal
Pin No.
Name
GND 1
GND 2
– 3
– 4
– 5
– 6
– 7
– 8
– 9
– 10
A14 11
A15 12
A16 13
A17 14
SW
A18 15
A19 16
– 17
PCE22_E 18
PCE21_E 19
– 20
RD 21
PCE22_O 22
PCE21_O 23
GND 24
– 60 –
EXWAITZ WAITZ
VWAITZ
Signal Signal
Pin No.
Name Name
– 25 D9
– 26 D8
– 27 D7
– 28 D6
A13 29 D5
A12 30 D4
A11 31 D3
A10 32 D2
A9 33 D1
A8 34 D0
A7 35 GND
A6 36 NC
A5 37 OWR
A4 38 –
A3 39 –
A2 40 –
A1 41 –
A0 42 –
D15 43 HWR
D14 44 –
D13 45 VMEM
D12 46 VMEM
D11 47 GND
D10 48 GND
Pin No.
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72