USB 2.0 Flash Drive Controller
Datasheet
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NAME | SYMBOL | TYPE | DESCRIPTION |
SM | nCD | IPU | This is the card detection signal from SM device to indicate if the device |
Card |
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| is inserted. |
Detection |
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| This pin has internal weak |
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| USB INTERFACE |
USB Bus | USB- | These pins connect to the USB bus data signals. | |
Data | USB+ |
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USB | LOOPFLTR |
| This pin provides the ability to supplement the internal filtering of the |
Transceiver |
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| transceiver with an external network, if required. |
Filter |
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USB | RBIAS |
| A precision 9.09K resistor is attached from ground to this pin to set the |
Transceiver |
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| transceiver’s internal bias currents. |
Bias |
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Termination | RTERM |
| A precision 1.5K resistor is attached to this pin from a 3.3V supply. |
Resistor |
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Full Speed | FS- | These pins connect to the USB- and USB+ pins through 31.6 ohm series | |
USB Data | FS+ |
| resistors. |
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| MEMORY/IO INTERFACE |
Memory | MD[7:0] | I/OPU8 | When ROMEN = 0, these signals are used to transfer data between the |
Data Bus |
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| internal CPU and the external program memory. |
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| When ROMEN = 1, internal weak pull up are activated to prevent these |
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| pins from floating. |
Memory | MA[15:0] | O8 | These signals address memory locations within the external memory. |
Address |
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Bus |
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Memory | nMWR | O8 | Program Memory Write; active low |
Read |
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Strobe |
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Memory | nMRD | O8 | Program Memory Read; active low |
Read |
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Strobe |
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Memory | nMCE | O8 | Program Memory Chip Enable; active low. |
Chip |
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Enable |
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| This signal shall be |
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| met: |
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| IDLE bit (PCON.0) is 1. |
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| INT2 is negated |
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| SLEEP bit of CLOCK_SEL is 1. |
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| This signal shall be asserted whenever any of the three conditions are |
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| no longer met. |
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I/O Read | nIOR | O8 | This is a active low I/O Read strobe signal of Xdata bus. |
Strobe |
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I/O Write | nIOW. | O8 | This is a active low I/O Write strobe signal of Xdata bus. |
Strobe |
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SMSC USB97C242 | Page 13 | Revision 1.4 |
DATASHEET