Branch Bus information

VBBC LEDs

From top to bottom:

LED1: "module selected from VME" (VME SEL)
LED2: "transfer" (BB XFR)
LED3: "Branch Error" (BB ERR)
LED4: "Arbitration Failure" (ARBFAIL)
      

Branchbus loading

Maximum length: 50 ft.

Branchbus signal designations

        GND : ground
AD00 - AD31 : data
PAR0 - PAR3 : parity for data bytes 0 through 3
         AS : address strobe
         DS : data strobe
       /DSV : "data strobe valid" driven by master during control cycle
        W/R : "write/read"
        /TC : "transfer complete"
      /WAIT : "wait"
     /RESET : reset
        /BE : bus error
      /CREQ : "channel request" driven by master to indicate that
              an arbitration cycle is starting
      /BREQ : "bus request"
       BGNT : "bus grant"
      

Branchbus connector pin assignments

Connector J1        J2

pin  1:   GND       GND
          AD00      RESET
          AD01      BE
          AD02      BREQ
          AD03      BGNT
          AD04      CREQ
          AD05      SPARE0
          AD06      PAR2
          AD07      AD16
          PAR0      AD17
          AD08      AD18
          AD09      AD19
          AD10      AD20
          AD11      AD21
          AD12      AD22
          AD13      AD23
          AD14      PAR3
          AD15      AD24
          PAR1      AD25
          AS        AD26
          DS        AD27
          DSV       AD28
          W/R       AD29
          TC        AD30
          WAIT      AD31