A49FL004 Datasheet, PDF (13/36 Pages) AMIC Technology – 4 Mbit CMOS 3.3Volt-only Firmware Hub/LPC Flash Memory

Multiple Device Selection
Multiple A49FL004 devices may be strapped to
increase memory densities in a system. The four ID
pins, ID[3:0], allow up to 16 devices to be attached to
the same bus by using different ID strapping in a
system, BIOS support, bus loading, or the attaching
bridge may limit this number. The boot device must
have an ID of “0000b” (determined by ID[3:0]);
subsequent devices use incremental numbering,
equal density must be used with multiple devices.
Multiple Device Selection for
Firmware Hub Memory Cycle
For Firmware Memory Read/Write cycles, hardware
strapping values on ID[3:0] must match the values in
IDSEL field. See Table x for multiple device selection
configurations. The A49FL004 will compare the
IDSEL field with ID[3:0] ‘s strapping values. If there is
a mismatch, the device will ignore the reminder of the
cycle.
Table 6: FWH Multiple Device Selection
Configuration
Device #
0 (Boot Device)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
ID[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
IDSEL
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
A49FL004
Multiple Device Selection for
LPC Memory Cycle
For LPC Memory Read/Write cycles, ID information is
included in the address bits of every cycle. The ID
bits in the address field are the reverse of the
hardware strapping. See Table x2 for multiple device
selection configurations. The A49FL004 will compare
these bits with ID[3:0]’s strapping values. If there is a
mismatch, the device will ignore the remainder of the
cycle.
Table 7: LPC Multiple Device Selection
Configuration
Device #
0 (Boot Device)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
ID[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Address Range
1111
1110
1101
1100
1011
1010
1001
1000
0111
0110
0101
0100
0011
0010
0001
0000
PRELIMINARY (September, 2005, Version 0.0)
12
AMIC Technology, Corp.