P R E L I M I N A R Y | AMD |
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PIN DESCRIPTIONS
Pins with Internal Pull Up or Pull Down Devices
Several pins of the Am79C930 device include internal pull up or pull down devices. With the exception of the RESET pin, these pins are fully programmable as inputs or outputs when the PCMCIA mode has been selected. A subset of these pins is programmable when the ISA Plug and Play mode has been selected. These pins will come up after RESET in the high impedance state with the pull up or pull down device actively determining the value of the pin, unless an external driving source overdrives the pull up or pull down device. VINITDN bit (MIR9[2]) is used to turn off all pull up and pull down devices.
The following list indicates those pins that contain pull up and pull down devices:
Following the RESET operation, the Am79C930 firm- ware or driver software should appropriately program the D bits of TIR and TCR registers, and then set the FN and EN bits of TIR and TCR registers to set the values and directions of each of these programmable pins. Once these operations have been performed, the soft- ware should then program the INITDN bit of MIR9 in or- der to disable all of the pull up and pull down devices. Unused programmable pins should be programmed for output mode, or may be left in the default high imped- ance state if an external pull down or pull up device is left connected to the pin. Unused programmable pins must not be programmed for input mode with no external source
PCMCIA Mode | Internal Device | Size of Internal |
Pin Name | Type | Device |
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USER[6]/IRQ5 | pull up | > 100K Ω |
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USER[5]/IRQ4 | pull up | > 100K Ω |
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USER[4]/LA17 | pull up | > 100K Ω |
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USER[3]/SA16 | pull up | > 100K Ω |
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USER[2]/LA19 | pull up | > 100K Ω |
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USER[1]/IRQ12 | pull down | > 100K Ω |
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USER[0]/RFRSH | pull down | > 100K Ω |
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LLOCKE/SA15 | pull down | > 100K Ω |
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ANTSLT/LA23 | pull up | > 100K Ω |
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TXDATA/LA20 | pull up | > 100K Ω |
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TXCMD/LA21 | pull down | > 100K Ω |
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RXC/IRQ10 | pull up | > 100K Ω |
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USER7/IRQ11 | pull up | > 100K Ω |
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LFPE | pull up | > 100K Ω |
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HFPE | pull up | > 100K Ω |
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RXPE | pull up | > 100K Ω |
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ANTSLT | pull down | > 100K Ω |
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TXCMD | pull up | > 100K Ω |
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TXPE | pull up | > 100K Ω |
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SDCLK | pull up | > 100K Ω |
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SDDATA | pull up | > 100K Ω |
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SDSEL[3] | pull up | > 100K Ω |
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SDSEL[2] | pull up | > 100K Ω |
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SDSEL[1] | pull up | > 100K Ω |
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ACT | pull up | > 100K Ω |
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LNK | pull up | > 100K Ω |
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TXMOD | pull up | > 100K Ω |
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STSCHG/BALE | pull up | > 100K Ω |
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TXC | pull up | > 100K Ω |
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Configuration Pins
PCMCIA
PCMCIA/ISA Bus Interface Select | Input |
The value of this pin will asynchronously determine the operating mode of the Am79C930 device, regardless of the state of the RESET pin and regardless of the state of the CLKIN pin. If the PCMCIA pin is tied to VCC, then the Am79C930 controller will be programmed for PCMCIA Bus Mode. If the PCMCIA pin is tied to VSS, then the Am79C930 controller will be programmed for ISA Plug and Play Bus Interface Mode.
Am79C930 | 25 |
