DSM2150F5V STMicroelectronics, DSM2150F5V Datasheet - Page 29

• Manufacturer Part Number: DSM2150F5V
• Description: DSM (Digital Signal Processor System Memory) for Analog Devices DSPs (3.3V Supply)
• Manufacturer: STMicroelectronics

Product Term Allocator
The CPLD has a Product Term Allocator. PSDsoft
Express
row and place product terms from one Macrocell to
another. This happens automatically in PSDsoft
Express
works will help you if your logic design does not
“fit”, in which case you may try selecting a different
pin or different OMC where the allocation resourc-
es may differ and the design will then fit. The fol-
lowing list summarizes how product terms are
allocated:
Each Macrocell may only borrow product terms
from certain other Macrocells. Product terms al-
ready in use by one Macrocell are not available for
another Macrocell. Product term allocation does
not add any propagation delay to the logic.
If an equation requires more product terms than
are available to it through product term allocation,
then “external” product terms are required, which
McellA0-McellA7 all have three native product
terms and may borrow up to six more
McellB0-McellB3 all have four native product
terms and may borrow up to five more
McellB4-McellB7 all have four native product
terms and may borrow up to six more.
™
™
, but understanding how allocation
uses the Product Term Allocator to bor-
consumes other OMC. This is called product term
expansion and also happens automatically in PS-
Dsoft Express
sion causes additional propagation delay because
an OMC is consumed by the expansion and it’s
output is rerouted (or fed back) into the AND array.
You can examine the fitter report generated by
PSDsoft Express to see resulting product term al-
location and product term expansion.
Loading and Reading the OMCs
Each of the two OMC blocks (8 OMCs each) occu-
pies a memory location in the DSP address space,
as defined in the csiop block MCELLA0-7 and
MCELLB0-7 (see
flops in each of the 16 OMCs can be loaded from
the data bus by a DSP. Loading the OMCs with
data from the DSP takes priority over internal func-
tions. As such, the preset, clear, and clock inputs
to the flip-flop can be overridden by the DSP. The
ability to load the flip-flops and read them back is
useful in such applications as loadable counters
and shift registers, mailboxes, and handshaking
protocols.
Data is loaded into the OMC on the trailing edge of
Write Strobe coming from CNTL0.
™
as needed. Product tern expan-
Table 4., page
DSM2150F5V
13). The flip-
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