SMSC LAN91C111
3.3.1Address Decoding Example
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A3 | A2 | A1 | ENABLE | NOTES | |
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0 | 0 | 0 | 300 | nBE0 | Assert nBE0 to enable the lowest byte |
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0 | 0 | 0 | 301 | nBE1 | Assert nBE1 to enable the second lowest byte |
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0 | 0 | 1 | 302 | nBE0 | Assert nBE0 to enable the lowest byte |
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0 | 0 | 1 | 303 | nBE1 | Assert nBE1 to enable the second lowest byte |
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0 | 1 | 0 | 304 | nBE0 | Assert nBE0 to enable the lowest byte |
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0 | 1 | 0 | 305 | nBE1 | Assert nBE1 to enable the second lowest byte |
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0 | 1 | 1 | 306 | nBE0 | Assert nBE0 to enable the lowest byte |
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0 | 1 | 1 | 307 | nBE1 | Assert nBE1 to enable the second lowest byte |
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3.3.2I/O Base Address 300h Decoding
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| The chart below shows the decoding of | I/O Base Address 300h: |
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A15 | A14 | A13 | A12 | A11 | A10 | A9 | A8 |
| A7 | A6 | A5 |
| A4 | A3 | A2 | A1 | A0 |
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0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
| 0 | 0 | 0 |
| 0 | 0 | 0 | 0 | 0 |
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3.4Asynchronous Interface
When the LAN91C111 working with an asynchronous bus, the read and write operation are controlled by the edges of nRD and nWR. ARDY is used for notifying the system that it should extend the access cycle. The leading edge of ARDY is generated by the leading edge of nRD or nWR while the trailing edge of ARDY is controlled by the internal LAN91C111 clock and, therefore, asynchronous to the bus.
SMSC AN 9.6 | 5 | Revision 1.0 |
APPLICATION NOTE