[net.micro] >32->64? bit micros; 68020 Pin Count, Placement Info

hull@hao.UUCP (Howard Hull) (12/20/84)

> 
> The main problem with 64 bit micros is the pin count on the chip
> (I am new to this discussion, so please ignore if this stuff has been
> pointed out before).  32 address lines and 64 data lines already make
> 96 pins on the chip!  Multiplexing these lines only defeats the purpose
> behind going to 64 bits to begin with.  I'm not saying that there will
> be no 64 bit micros, but they are likely to be bit-sliced machines.

No need to worry if chip manufacturers will be concerned over the pin count.
The Motorola 68020 has 114 pins!
>
> The greatest derangement of the mind is to believe in something
> because one wishes it to be so - Louis Pasteur
> 
>                                               James Giles
It looks like this:
			N * * * * * * * * * * * * *
			M * * * * * * * * * * * * *
			L * * * * * * * * * * * * *
			K * * *                 * *
			J * * *                 * *
			H * * *                 * *
			G * * *               * * *
			F * * *                 * *
			E * * *                 * *
			D * * *                 * *
			C * * * * * * * * * * * * *
			B * * * * * * * * * * * * *
			A * * * * * * * * * * * * *
			                    1 1 1 1
			  1 2 3 4 5 6 7 8 9 0 1 2 3

	Pin#	Function	Pin#	Function	Pin#	Function
	A1	BGACK~		D1	Vcc		K1	GND
	A2	A1		D2	Vcc		K2	HALT~
	A3	A31		D3	N.C.		K3	N.C.
	A4	A28		D4-D11	-		K4-K11	-
	A5	A26		D12	A4		K12	D1
	A6	A23		D13	A3		K13	D0
	A7	A22					L1	AS~
	A8	A19					L2	R/W~
	A9	Vcc		E1	FC0		L3	D30
	A10	GND		E2	RMC~		L4	D27
	A11	A14		E3	Vcc		L5	D23
	A12	A11		E4-E11	-		L6	D19
	A13	A8		E12	A2		L7	GND
				E13	OCS~		L8	D15
							L9	D11
							L10	D7
	B1	N.C.		F1	SIZ0		L11	N.C.
	B2	BG~		F2	FC2		L12	D3
	B3	BR~		F3	FC1		L13	D2
	B4	A30		F4-F11	-
	B5	A27		F12	N.C.		M1	DS~
	B6	A24		F13	IPEND~		M2	D29
	B7	A20					M3	D26
	B8	A18					M4	D24
	B9	GND		G1	ECS~		M5	D21
	B10	A15		G2	SIZ1		M6	D18
	B11	A13		G3	DBEN~		M7	D16
	B12	A10		G4-G10	-		M8	Vcc
	B13	A6		G11	Vcc		M9	D13
				G12	GND		M10	D10
				G13	Vcc		M11	D6
							M12	D5
	C1	RESET~					M13	D4
	C2	CLOCK		H1	CDIS~
	C3	N.C.		H2	AVEC~		N1	D31
	C4	A0		H3	DSACK0~		N2	D28
	C5	A29		H4-H11	-		N3	D25
	C6	A25		H12	IPL2		N4	D22
	C7	A21		H13	GND		N5	D20
	C8	A17					N6	D17
	C9	A16					N7	GND
	C10	A12		J1	DSACK1~		N8	Vcc
	C11	A9		J2	BERR~		N9	D14
	C12	A7		J3	GND		N10	D12
	C13	A5		J4-11	-		N11	D9
				J12	IPL0~		N12	D8
				J13	IPL1~		N13	N.C.

The Vcc and GND pins are separated into three groups to provide individual
power supply connections for the address bus buffers, data buffers, and all
other output buffers and internal logic.

	Group			Vcc			GND
	Address Bus		A9			A10,B9
	Data Bus		M8,N8			L7,N7
	Logic			D1,D2,E3,G11,G13	G12,H13,J3,K1

Disclaimer:  While copied with great care from Motorola publication BR-243,
"MC68020 Technical Summary" the Data provided are for a virtual device for
which Motorola states "Specifications and information herein are subject to
change without notice."  Any smoke obtained from a real device by using this
preliminary pinout is the responsibility of the user and not the submitter of
this net article or his employer.
								Howard Hull
        {ucbvax!hplabs | allegra!nbires | harpo!seismo } !hao!hull