MD2241-D128-V3 M-Systems Inc., MD2241-D128-V3 Datasheet - Page 33

• Manufacturer Part Number: MD2241-D128-V3
• Description: Diskonchip Dimm Plus
• Manufacturer: M-Systems Inc.

9.3.4 8-Bit/16-Bit Bus Width Interface
DiskOnChip DIMM Plus can be configured for either 8-bit or 16-bit bus operations via the IF_CFG signal.
8-Bit (Byte) Data Access Mode
When configured for 8-bit operation, IF_CFG should be negated. Data should then be driven only on the low data
bus signals D[7:0]. D[15:8] and BHE# are internally pulled up and may be left floating.
16-Bit (Word) Data Access Mode
When configured for 16-bit operation, IF_CFG should be asserted. The following definition is compatible with 16-
bit platforms using the BHE#/BLE# protocol:
Table 3 shows the active data bus lanes in 16-bit configuration.
TrueFFS Driver Modifications
TrueFFS supports a wide range of OSs (see section 6.1.1). The TrueFFS driver is set to work in 8-bit data access
mode as the default. To support 16-bit data access modes and their related memory window allocations, TrueFFS
must be modified. In Windows CE and Windows NT-Embedded, these changes can be implemented through the
Registry Entries. In all other cases, some minor customization is required in the driver. Please refer to the
Installation Manual of each specific driver for further information.
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When the hosts’ BLE# signal asserts DiskOnChip A[0], data is valid on D[7:0].
When the hosts’ BHE# signal asserts DiskOnChip BHE#, data is valid on D[15:8].
When both A[0] and BHE# are at logic 0, data is valid on D[15:0].
No data is transferred when both BHE# and A[0] are logic 1.
16-bit hosts that do not support byte transfers may hardwire the A[0] and BHE# inputs to logic 0.
BHE#
0
0
1
1
Inputs
Table 3: Active Data Bus Lanes in 16-bit Configuration
A0
0
1
0
1
Preliminary Data Sheet, Rev. 1.2
D[7:0]
Data Bus Activity
D[15:8]
Transfer Type
No operation
Even Byte
Odd Byte
Word
DiskOnChip DIMM Plus
94-SR-002-08-8L