315-5680 and 315-5681 Pinouts

The Sega 315-5680 and 315-5681 are custom ICs only found in certain TecToy Master System III Compact and Master System Super Compact revisions. The 315-5680 is an I/O controller and the 315-5681 is a VDP similar in function to the 315-5246. Both were manufactured by NEC and are 80-pin QFP surface mount chips.

These pinouts were made by performing continuity checks and close examination of the board with both chips depopulated. Note that these pinouts are not totally complete as there are several pins which are unused and whose function is unknown. Until official documentation is obtained, these are the only pinouts of these chips known to exist anywhere online.

315-5680 (I/O)

Pin Number	Description	Pin Number	Description	Pin Number	Description	Pin Number	Description
1	A7	21	VRAM CE	41	2RI	61	CE2?
2	A6	22	NC (Unknown)	42	2TL	62	CE3
3	A0	23	NC (Unknown)	43	2TR	63	CE4?
4	IOREQ	24	NC (Unknown)	44	2TH	64	Reset
5	WR	25	GND	45	AD0	65	KILLGA
6	RD	26	GND	46	AD1	66	NC (Unknown)
7	AD12	27	H-L	47	AD2	67	VCC
8	AD11	28	NC (Unknown)	48	AD3	68	GND
9	AD10	29	1UP	49	AD4	69	CSRAM
10	AD9	30	1DW	50	AD5	70	MREQ
11	AD8	31	1LE	51	AD6	71	GND
12	VCC	32	1RI	52	AD7	72	VCC
13	AD7	33	GND	53	GND	73	D7
14	AD6	34	VCC	54	AD8	74	D6
15	AD5	35	1TL	55	AD9	75	D5
16	AD4	36	1TR	56	AD10	76	D4
17	AD3	37	1TH	57	AD11	77	D3
18	AD2	38	2UP	58	AD12	78	D2
19	AD1	39	2DW	59	CE0	79	D1
20	AD0	40	2LE	60	CE1	80	D0

315-5681 (VDP)

Pin Number	Description	Pin Number	Description	Pin Number	Description	Pin Number	Description
1	KBSEL	21	NMI In	41	VCC	61	AD13
2	CSRAM	22	NC (Unknown)	42	AD0	62	AD14
3	EXM1	23	Reset	43	AD1	63	NC (Unknown)
4	EXM2	24	H-L	44	AD2	64	AD15
5	A14	25	CBT?	45	AD3	65	NTSC/PAL
6	NC (Unknown)	26	HI-OUT	46	AD4	66	RD
7	NC (Unknown)	27	Red	47	NC (Unknown)	67	WR
8	NC (Unknown)	28	Green	48	AD5	68	IOREQ
9	GND	29	Blue	49	NC (Unknown)	69	A0
10	NC (Unknown)	30	Sync	50	AD6	70	A6
11	PSG	31	Ys?	51	NC (Unknown)	71	A7
12	NC (Unknown)	32	GND	52	AD7	72	INT
13	NC (Unknown)	33	NC (Unknown)	53	AD8	73	D0
14	GND	34	CLK	54	NC (Unknown)	74	D1
15	NC (Unknown)	35	XTAL1	55	AD9	75	D2
16	VCC	36	XTAL2	56	NC (Unknown)	76	D3
17	NC (Unknown)	37	WE1	57	AD10	77	D4
18	A15	38	WE0	58	NC (Unknown)	78	D5
19	MREQ	39	VRAM OE	59	AD11	79	D6
20	NMI	40	VRAM CE	60	AD12	80	D7

315-5680 and 315-5681 Pinouts

315-5680 (I/O)

315-5681 (VDP)

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