Kenwood MB-430, PS-50, SP-430, PS-430, AT-440, VS-1, YK-88C, YK-88S TPD8255AC-5 Control unit IC2

SEMICONDUCTO R

t PD8251AC (Control unit IC54)

	Data bus
					Data	ra n
		D7o.DI4			bus	m i
					buffer	buffer
7404 2 .4576MHz						(P — SI
	P B7	RESET
		~•~
yl PD7800					R/ R
	E 8 ® C/D		~		contro l
					I ogic
	R D	RD •		•
	WR m~C S :4~•
SN74L5138	Ye L	DS R	•p
CTS	l0	DTR				Receiv e
	5				MODE M
RTS 6 O 4 041 3						contro I
				•	contro l
	® SN7404	CTS	:
			•

Inne r data bus

tPD8255AC-5 (Control unit IC2, 53)

TS-440S

	SN7404		5s
TXD	5	6	•	TX D
	8_ w9		0	RX D

Not use

Not use

05 (404010 pin ( Bo rate : 4800 )

R X

RD Y 5PD7800 INTI 12 pi n

RX C

SYNDET/BD Not us e

Group A

Group A

Dat a

bu s buffer

contro l

Port AI/O Port A

(8 bit )

I/O Port C

Group B

Port C (Lower 4 bit )

R/ W

Group B

Group B

control

74LS 13 8

i1 At IC2 : Y3 I2

ill At IC53 Y2 I3

contro lPort BI/O Port B

(8 bit )

Basic functio n
A t	A D	CS	RD	WR		Functio n
0	0	0	0	1	Data bus °-- Port A
0	1	0	0	1	Data bus	Port B
1	0	0	0	1	Data bus	Port C
0	0	0	1	0	Port A — Data bu s
0	1	0	1	0	Port B	Data bu s
1	0	0	1	0	Port C — Data bu s
1	1	0	1	0	Control register t— Data bu s
x	x	1	x	x	Data bus is in high impedanc e
					statu s
1	1	0	0	1	Combination is inhibited

"0" shows low level (L ) "1" shows high level (H)

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