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  | In addition, the USER5/IRQ4 pin may be used to produce interrupts  | |||||
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  | to the 80188 embedded controller. This capability is controlled by  | |||||
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  | the ENXCHBSY bit of TCR28 and the CHBSYCU bit of TIR5 and  | |||||
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  | operates independently of the bits mentioned above.  | |||||
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  | The control of the function of the USER5/IRQ4 pin is described in  | |||||
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U1INTCNT | 00b  | USER1 Interrupt control bits. The USER1/IRQ12 pin can be used  | |||||||
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  | to signal an interrupt to the 80188 embedded controller. The  | |||||
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  | U1INTCNT bits have the following interpretation and operate inde-  | |||||
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  | pendently of the operating mode of the Am79C930 device (i.e.,  | |||||
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  | the U1INTCNT bits operate in both PCMCIA and ISA Plug and  | |||||
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  | Play modes.): | 
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  | U1INT Bit  | 
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  | U1INTCNT | 
  | USER1 Pin  | (TCR11[3])  | 
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  | TCR7[4:3]  | 
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  | X  | 0 => interrupt  | 
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  | disabled  | 
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  | rising edge  | 1 => interrupt  | 
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  | signaled  | 
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  | falling edge  | 1 => interrupt  | 
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  | signaled  | 
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  | rising or  | 1 => interrupt  | 
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  | falling edge  | signaled  | 
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  | Note that the USER1 pin function has no effect on the use of the  | |||||
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  | USER1/IRQ12 pin as an interrupt signaling pin. If the  | |||||
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  | USER1/IRQ12 pin is to be used as a 80188 controller interrupt  | |||||
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  | source in the ISA Plug and Play mode, then it is imperative that the  | |||||
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  | ISA Plug and Play resource data structure loaded into the accom-  | |||||
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  | panying flash device as part of the Am79C930 device based design  | |||||
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  | should not include IRQ12 as a choice of IRQ level for possible se-  | |||||
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  | lection by the ISA Plug and Play configuration software. When this  | |||||
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  | procedure is followed, then the system designer can be assured  | |||||
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  | that the IRQ12 function will not be used by the Am79C930 device,  | |||||
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  | and therefore, the USER1/IRQ12 pin will remain in the   | |||||
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  | ance state and will be available for connection to an interrupt gener-  | |||||
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  | ating source in the design.  | 
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2  | TXCMDT | 0  | 
  | TXCMD Data. The value written to the TXCMDT bit is used in some  | |||||
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  | modes to determine the output value of the TXCMD/LA21 pin.  | |||||
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  | Reads from TXCMDT always return the current value of the  | |||||
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  | TXCMD/LA21 pin.  | 
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  | The control of the function of the TXCMD/LA21 pin is described in  | |||||
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1  | ANTSLTLD | 1  | 
  | ANTSLTL Data. The value that is written to this bit will be driven out  | |||||
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  | to the ANTSLT pin of the Am79C930 device when the ANTSLTLFN  | |||||
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  | bit of TCR30 has been set to a 1 and the ANTSLTLEN bit of TCR15  | |||||
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  | has also been set to a 1 and the PCMCIA pin is set to 1. The value  | |||||
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  | that is read from this bit represents the current value of the ANTSLT  | |||||
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  | pin of the Am79C930 device.  | 
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  | A complete description of the control of the function of the ANTSLT  | |||||
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0  | TXDATALD | 1  | 
  | TXDATAL Data. The value that is written to this bit will be driven out  | |||||
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  | to the TXDATA pin of the Am79C930 device when the TXDATALFN  | |||||
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  | bit of TCR30 has been set to a 1 and the TXDATALEN bit of TCR15  | |||||
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  | Am79C930 | 
  | 109 | 
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