Table 7-14. Rabbit 3000 Reset Sequence and State of I/O Pins

Pin Name

Direction

/RESET Low*

Post-Reset

Recognized by CPU

 

 

 

 

 

 

 

/RESET

Input

Low or High

High

 

 

 

 

CLK

Output

High

Operational

 

 

 

 

CLK32K

Input

Not Affected

Not Affected

 

 

 

 

RESOUT

Output

High

Low

 

 

 

 

XTALA1

Input

Not Affected

Not Affected

 

 

 

 

XTALA2

Output

Not Affected

Not Affected

 

 

 

 

A[19:0]

Output

Last Value

0x00000

 

 

 

 

D[7:0]

Bidirectional

High Z

High Z

 

 

 

 

/WDTOUT

Output

High

High

 

 

 

 

STATUS

Output

High

Operational

(as /IFTCH1)

 

 

 

 

 

 

 

SMODE[1:0]

Input

Not Affected

Not Affected

 

 

 

 

/CS0

Output

High

Operational

 

 

 

 

/CS1

Output

High Z

High

 

 

 

 

/CS2

Output

High

High

 

 

 

 

/OE0

Output

High

Operational

 

 

 

 

/OE1

Output

High

High

 

 

 

 

/WE0

Output

High

High

 

 

 

 

/WE1

Output

High

High

 

 

 

 

/BUFEN

Output

High

High

 

 

 

 

/IORD

Output

High

High

 

 

 

 

/IOWR

Output

High

High

 

 

 

 

PA[7:0]

Input/Output

zzzzzzzz

zzzzzzzz

 

 

 

 

PB[7:0]

Input/Output

00zzzzzz

00zzzzzz

 

 

 

 

PC[7:0]

4 In/4 Out

z0z1z1z1

z0z1z1z1

 

 

 

 

PD[7:0]

Input/Output

zzzzzzzz

zzzzzzzz

 

 

 

 

PE[7:0]

Input/Output

zzzzzzzz

zzzzzzzz

 

 

 

 

PF[7:0]

Input/Output

zzzzzzzz

zzzzzzzz

 

 

 

 

PG[7:0]

Input/Output

zzzzzzzz

zzzzzzzz

 

 

 

 

* A low is recognized internally by the processor after a reset

The default state of the I/O ports after the completion of the reset and initializa- tion sequences

96

Rabbit 3000 Microprocessor

Page 105
Image 105
Jameco Electronics 2000 manual Rabbit 3000 Reset Sequence and State of I/O Pins