Epson LQ-2550 Technical Manual page 251

REV.-A
The wPD78 10HG is a one-chip 8-bit CPU and includes two 8-bit timers, an 8-bit A/D
RAM, and a serial interface.
The main features of this chip are as follows:
256-byte RAM
Direct addressing of up to 64K bytes
8-bit A/D converter
. 158 instructions
1 KS instruction cycle (12 MHz)
. 16-bit timer/event counter
Two 8-bit timers
Interrupts (3 internal, 8 external)
General purpose serial interface
Zero crossing detection
Standby function
Built-in clock oscillator circuit
N M O S
show the pin diagram and the internal block diagram. Table A-3 shows the functions
Figures A-5 and A-6
of each terminal.
—
—
— 3
—
—
+ 6
7
—
— 8
9
—
10
—
11
—
12
—
13
—
14
—
—
16
—
TXD — 17
18
RXD —
—
—
PCS —
23
24
—
25
2 6
I N T 1 —
— 27
28
—
R E S E T
—
2 9
x2 — 30
xl — 31
— 32
Figure A-5. pPD781 OHG Pin Diagram
A-6
6 3 —
6 2 —
61 —
P 0 6
60 —
5 9 —
5 8 —
57 —
P132
—
54 — PF7
53 — PF6
52 —
PF5
51 —
PF3
50 —
4 9 — PF2
48 —
PF 1
47 —
PFO
46 —
ALE
45 —
44 —
43 —
A V
C C
42 —
41 —
A N 7
40 —
A N 6
39 —
A N 5
3 8 —
A N 4
37 —
A N 3
36 —
A N 2
1
35 —
AN
34 — ANO
33 — AV SS
converter, 256-byte
,