Texas Instruments TMS320C3x User Manual
Page 270

Memory Interface Signals
9-4
Table 9–1. Primary Bus Interface Signals
Signal
Type
†
Description
Value
After Reset
Idle Status
STRB
O/Z
Primary interface access strobe
1
1
R/W
O/Z
Specifies memory read (active high) or write
(active low) mode
1
1
HOLD
I
Hold external memory interface
NA
‡
Ignored
HOLDA
O/Z
Hold acknowledge for external memory interface
1
1
RDY
I
Indicates external primary interface is ready to
be accessed
NA
‡
Ignored
A (23–0)
O/Z
Primary address bus. When the primary bus
address lines are not in high-impedance state
due to HOLD signal, they keep in the last exter-
nal primary bus access.
HI
Address of last external
bus access
D (31–0)
I/O/Z
Primary data bus. These signals go to high-
impedance between write accesses.
HIZ
HIZ
† I
Input
O Output
Z High impedance
‡ NA means not affected.