Programming Model

 

 

 

 

 

 

 

 

 

 

 

 

 

Recovery Time

Recovery Time

 

RT1

RT0

with IP = 8 MHz

with IP = 32 MHz

 

 

 

 

 

 

0

0

0 microseconds

0 microseconds

 

 

 

 

 

 

0

1

2 microseconds

0.5 microsecond

 

 

 

 

 

 

1

0

4 microseconds

1 microsecond

 

 

 

 

 

 

1

1

8 microseconds

2 microseconds

 

 

 

 

 

 

back I/O and/or ID accesses are ensured if a single size

 

access is followed by a single size access, or if a double

 

size, longword access is followed by a single or double

 

size access. However, if a single size (or byte or word) I/O

 

or ID access is followed by a double size I/O access, the

 

double size access may be allowed to happen before the

 

recovery times for both a and b (or both c and d) have

 

expired. This behavior is avoided if I/O accesses are

 

restricted to single size only, or if they are restricted to

 

double size, longword only and the double size accesses

 

are not interspersed with ID accesses. Note that memory

 

accesses do not affect, nor are they affected by, this

 

behavior.

a_ERR

This bit reflects the state of the ERROR* signal from the

 

IP_a interface.

b_ERR

This bit reflects the state of the ERROR* signal from the

 

IP_b interface.

c_ERR

This bit reflects the state of the ERROR* signal from the

 

IP_c interface.

d_ERR

This bit reflects the state of the ERROR* signal from the

 

IP_d interface.

4

http://www.mcg.mot.com/literature

4-27

Page 263
Image 263
Motorola MVME172 manual Aerr, Berr, Cerr, Derr