LEV EL 1 D IA G N O S T IC S ERRO R R ET U R N SRAM ADDRESS ERROR TESTFormat of code:JffiM0RY:03:ww Date TimeADDR: ssss:ooooEXP DATA: xxxx, OBS DATA: yyyyWhere, wwwfor DETAIL 01,xxxxyyyyfor DETAIL 02,ssssooooxxxxyyyyfor DETAIL 03,ssssooooX XyyDetail codeSegement of expected addressSegment of observed addressSegment of address or errorAlways zeroExpected address (A8 - A15)Observed address (A8 - A15)Segment address of errorAlways zeroExpected address (A0 - A7)Observed address (A0 - A7)Detail code:01 Segment conflict (A16 - 20A)02 Upper address conflict (A8 - AI 5)03 Low address conflict (A0 -A7)Repair Procedure 03RAM ADDRESS ERROR will return Detail codes that helpisolate problems with the system address bus. TheADDRESS PATH is checked in the hardware for integrityalong isolated bus components. The ADDRESS PATH ishardware divided as low order address (8 bits), highorder address (8 bits), and segment address (4 bits).Each address path has its own data latches and busdrivers. The Detail code returned by the RAM ADDRESSTEST specifies the ADDRESS PATH in the hardware thatcould be defective. Comparing the expected addresswith the observed can provide indications of whichaddress line(s) are failing. Evaluation of bus driverinput/output characteristics is recommended; suspectintermittent IC failure.5-20
