Table 10-1shows how the eight I/O bank control registers are organized.

Table 10-1. I/O Bank x Control Register

 

I/O Bank x Control Register

(IB0CR)

(Address = 0x0080)

 

 

 

 

(IB1CR)

(Address = 0x0081)

 

 

 

 

(IB2CR)

(Address = 0x0082)

 

 

 

 

(IB3CR)

(Address = 0x0083)

 

 

 

 

(IB4CR)

(Address = 0x0084)

 

 

 

 

(IB5CR)

(Address = 0x0085)

 

 

 

 

(IB6CR)

(Address = 0x0086)

 

 

 

 

(IB7CR)

(Address = 0x0087)

Bit(s)

 

Value

 

Description

 

 

 

 

 

 

7:6

 

00

Fifteen wait states for accesses in this bank.

 

 

 

 

 

 

 

 

01

Seven wait states for accesses in this bank.

 

 

 

 

 

 

 

 

10

Three wait states for accesses in this bank.

 

 

 

 

 

 

 

 

11

One wait state for accesses in this bank.

 

 

 

 

 

 

5:4

 

00

The Ix signal is an I/O chip select.

 

 

 

 

 

 

 

 

01

The Ix signal is an I/O read strobe.

 

 

 

 

 

 

 

 

10

The Ix signal is an I/O write strobe.

 

 

 

 

 

 

 

 

11

The Ix signal is an I/O data (read or write) strobe.

 

 

 

 

 

 

 

0

Writes are not allowed to this bank. Transactions are normal in every other way;

3

 

only the write strobe is inhibited.

 

 

 

 

 

 

 

 

 

 

 

1

Writes are allowed to this bank.

 

 

 

 

 

 

 

 

2

 

0

I/O strobe (Ix) is active low.

 

 

 

 

 

 

 

 

1

I/O strobe (Ix) is active high.

 

 

 

 

 

 

 

 

 

 

 

 

1:0

 

 

These bits are ignored.

 

 

 

 

 

 

 

 

146

Rabbit 3000 Microprocessor

Page 155
Image 155
Jameco Electronics 2000, 3000 manual I/O Bank x Control Register