Clocking Frequencies for the TNT5002 Chip Hardware: GPIB>>ASICs/OEM Products>>TNT5002
Problem: Are there limits on the frequency at which you can clock the TNT5002? Solution: The TNT5002 chip can operate in two modes: PCI4882 (with PCI & GPIB clocked regions) and GEN4882 (which only uses the GPIB clock). The PCI clock is driven by the PCI_CLK line and must be 33MHz for PCI compliance. The GPIB clock can be run off of the PCI clock if the USE_PCI_CLK line is asserted. Otherwise, the GPIB circuitry is clocked off of the EXT_CLK line (the USE_PCI_CLK line must be unasserted). The EXT_CLK line can be driven with signals between 33MHz and 40MHz. To achieve the HS488 standard, the EXT_CLK must be driven at 40MHz. See the TNT5002 User Manual linked below for further mode and clocking information. For more information regarding the consequences of clocking the TNT5002 below 40MHz, see the TNT4882 User Manual also linked below, as the GPIB portion of the TNT5002 is handled by the TNT4882 chip. NOTE: The TNT5002 has not been tested at clocking frequencies of less than 33MHz and as such, this is not an option supported by National Instruments. Related Links: TNT5002 Technical Reference Manual TNT4882 Programmer Reference Manual Attachments:
Report Date: 01/29/2007 Last Updated: 01/30/2007 Document ID: 45SJPVZC |
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