Intel 80C186XL, 80C188XL user manual Starting Address

CHIP-SELECT UNIT

Table 6-5. MCS Block Size and Start Address Restrictions

		MPCS Block Size Bits						Block Size	MMCS Start Address
M6	M5		M4	M3	M2	M1	M0	(Kbytes)	Restrictions
0	0		0	0	0	0	1	8	None
0	0		0	0	0	1	X	16	U13 must be zero.
0	0		0	0	1	X	X	32	U14:13 must be zero.
0	0		0	1	X	X	X	64	U15:13 must be zero.
0	0		1	X	X	X	X	128	U16:13 must be zero.
0	1		X	X	X	X	X	256	U17:13 must be zero.
1	X		X	X	X	X	X	512	U18:13 must be zero.
									NOTE: If U19 is one, will overlap	UCS.

X= don’t care, but should be 0 for future compatibility.

Starting Address Ending Address

Block Size is

defined by M6:0

Base + 3/4 Block Size

Base + 1/2 Block Size

Base + 1/4 Block Size

MCS Base (Defined by U19:13)

MCS3 Active Range

MCS2 Active Range

MCS1 Active Range

MCS0 Active Range

Base + (Block Size-1)

Base + (3/4 Block Size-1)

Base + (1/2 Block Size-1)

Base + (1/4 Block Size-1)

Memory Map

A1136-0C

Figure 6-10. MCS3:0 Active Ranges

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