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Chip Errata
DSP56007 Digital Signal Processor
Mask: 1F91R
ERRATA
Errata Description
1. Specification timings #83, #84, and #87 in the data sheet provide 1 x T
C
less than
specified; e.g.,
a. specification #83 measures 8 x T
C
(12 x T
C
) instead of 9 x Tc (13 x T
C
) in the
EMI fast (slow) DRAM timing mode, respectively;
b. specification #84 measures 4 x T
C
- 9 (6 x T
C
- 9) instead of 5 x T
C
- 9 (7 x T
C
- 9)
in the EMI fast (slow) DRAM timing mode, respectively; and
c. specification #87 measures 4 x T
C
- 15 (6 x T
C
- 15) instead of 5 x T
C
- 15 (7 x T
C
-
15) in the EMI fast (slow) DRAM timing mode, respectively.
Workaround:
The refresh t
RAS
timing requirement in a 60 ns DRAM device is not
met when the DSP56007FJ66 runs at full speed (66 MHz) and the EMI is pro-
grammed in the "fast" DRAM timing mode (EDTM = 0 in ECSR). In this case, only
spec timing #84 does not meet the requirement. To ensure correct refresh of a
60 ns DRAM connected to DSP56007FJ66 running at 66 MHz and accessing the
DRAM using the EMI fast timing mode, one of the following methods is recom-
mended:
a. Access the DRAM device without using the internal refresh timer, as de-
scribed in Section 3.4.1 of the user's manual. This method is possible if the data
transfer rate is high.
b. Refresh the DRAM device in a burst manner, as described in Section 3.4.2.2 of
the user's manual. This method divides the real time audio processing window
into two portions.
During the first portion, DRAM data transfers without refresh (EREF = 0) are
done using the EMI fast timing mode (EDTM = 0).
During the second portion, when EMI is not doing data transfers, a burst of
refresh cycles is enabled (EREF = 1) using the EMI slow timing mode
(EDTM = 1).
Applies
to Mask
1F91R
Motorola, Digital Signal Processing Division
6501 William Cannon Drive West, Austin, Texas 78735-8598
pg. 1 /kre/3/1/96
©
1995, 1996 Motorola
Chip Errata
DSP56007 Digital Signal Processor
Mask: 1F91R
NOTES
1. An over-bar (for example, xxxx) indicates an active-low signal.
2. The letters seen to the right of the errata tell which DSP56007 mask numbers apply.
-end-
DSP56007 Errata
©
1995, 1996 Motorola
pg. 2 /kre/3/1/96

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