Master Rabbit

First Slave Rabbit

D0–D7

SD0–SD7

+

/IORD

/SRD

 

/IOWR

/SWR

 

A0

SA0

SMODE0

A1

SA1

CLK

/XTALB1

SMODE1

portout

/RESET

INT0A

/SLAVEATTN

 

/I7

/SCS

 

INT1A

 

 

/I6

 

 

 

Second Slave Rabbit

 

 

+

Reset

 

 

Pulldown

 

SMODE0

 

 

 

/SLAVEATTN

SMODE1

 

/SCS

 

Figure 13-4. Typical Connection Slave Rabbit to Master Rabbit

The slave port lines are shown in Figure 13-1.The function of these lines is described below.

SD0–SD7—These are bidirectional data lines, and are generally connected to the data bus of the master processor. Multiple slaves can be connected to the data bus. The slave drives the data lines only when /SCS and /SRD are both pulled low.

SA1, SA0—These are address lines used to select one of the four data registers of the slave interface. Normally these lines are connected to the low-order address lines of the master. The master always drives these lines which are always inputs to the slave.

/SCS—Input. Slave chip select. The slave ignores read or write requests unless the chip select is low. If a Rabbit is used as a master, this line can be connected to one of the master’s programmable chip select lines /I0–/I7.

/SRD—Input. If /SCS is also low, this line pulled low causes the contents of the register selected by the address lines to be driven on the data bus. If a Rabbit is used as a master, this line is normally connected to the global I/O read strobe /IORD.

/SWR—Input. If /SCS is also low, this line causes the data bits on the data bus to be clocked into the register selected by the address lines on the rising edge of /SWR or /SCS, whichever rises first. If a Rabbit is used as a master, this line is normally con- nected to the global I/O write strobe /IOWR.

User’s Manual

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Jameco Electronics 3000, 2000 manual Typical Connection Slave Rabbit to Master Rabbit