10.I/O BANK CONTROL REGISTERS

The pins of Port E can be set individually to be I/O strobes. Each of the eight possible I/O strobes has a control register that controls the nature of the strobe and the number of wait states that will be inserted in the I/O bus cycle. Writes can also be suppressed for any of the strobes. The types of strobes are shown in Figure 10-1.Each of the eight I/O strobes is active for addresses occupying 1/8th of the 64K external I/O address space.

ADDR

write data

write strobe

T1 Tw T2

valid

valid

read data

read strobe

chip select strobe

valid

External I/O Timing (with 1 wait state)

Figure 10-1. External I/O Bus Cycles

User’s Manual

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Jameco Electronics 3000, 2000 manual 10. I/O Bank Control Registers, Write data Write strobe T1 Tw T2