
Data Addendum
May 2001
DSP16410C Digital Signal Processor
Agere Systems Inc.
32
8 Timing Characteristics and Requirements
(continued)
8.9 System and External Memory Interface
In the following timing diagrams and associated tables:
I
The designation
ENABLE
refers to one of the following pins: EROMN, ERAMN, or EION. The designation
ENABLES
refers to all of the following pins: EROMN, ERAMN, and EION.
I
The designation
ERWN
refers to the following:
—
The ERWN0 pin if the external data bus is configured as 16 bits, i.e., if the ESIZE pin is logic low.
—
The ERWN1 and ERWN0 pins if the external data bus is configured as 32 bits, i.e., if the ESIZE pin is logic
high.
—
The ERWN1, ERWN0, and EA0 pins if the external data bus is configured as 32 bits, i.e., if the ESIZE pin is
logic high, and if the memory access is synchronous.
I
The designation
EA
refers to the following:
—
The external address pins EA[18:0] and the external segment address pins ESEG[3:0] if the external data bus
is configured as 16 bits, i.e., if the ESIZE pin is logic low.
—
The external address pins EA[18:1] and the external segment address pins ESEG[3:0] if the external data bus
is configured as 32 bits, i.e., if the ESIZE pin is logic high.
I
The designation
ED
refers to the following:
—
The external data pins ED[31:16] if the external data bus is configured as 16 bits, i.e., if the ESIZE pin is logic
low.
—
The external data pins ED[31:0] if the external data bus is configured as 32 bits, i.e., if the ESIZE pin is logic
high.
I
The designation
ATIME
refers to IATIME (
ECON0
[11:8]) for accesses to the EIO space, YATIME (
ECON0
[7:4])
for accesses to the ERAM space, or XATIME (
ECON0
[3:0]) for accesses to the EROM space.
ECKO reflects CLK, i.e.,
ECON1
[1:0] = 1.
Figure 15. Enable and Write Strobe Transition Timing
Table 24. Timing Characteristics for Memory Enables and
ERWN
Abbreviated
Reference
t102
t103
t112
t113
Parameter
Min
Max
Unit
ECKO to
ENABLE
Active (high to low)
ECKO to
ENABLE
Inactive (high to high)
ECKO to
ERWN
Active (high to low)
ECKO to
ERWN
Inactive (high to high)
0.5
0.5
0.5
0.5
4
4
4
4
ns
ns
ns
ns
ENABLE
t102
ERWN
t113
t112
t103
ECKO
V
OH
–
V
OL
–