AD7819t1t2EXT CONVSTt3tPOWER-UPINT CONVSTBUSYCS/RDDB7–DB08 MSBs Figure 13. Mode 1 Operation EXT CONVSTtPOWER-UPt1INT CONVSTt3BUSYCS/RDDB7–DB08 MSBs Figure 14. Mode 2 Operation PARALLEL INTERFACE BUSY goes logic high. Care must be taken to ensure that a read The parallel interface of the AD7819 is eight bits wide. The out- operation does not occur while BUSY is high. Data read from put data buffers are activated when both CS and RD are logic the AD7819 while BUSY is high will be invalid. For optimum low. At this point the contents of the data register are placed on performance the read operation should end at least 100 ns (t the 8-bit data bus. Figure 15 shows the timing diagram for the par- 8) prior to the falling edge of the next CONVST. allel port. The Parallel Interface of the AD7819 is reset when CONVSTt2t3t8BUSYt1CSt4t5RDt7t6DB7–DB08 MSBs Figure 15. Parallel Port Timing REV. B –9–