PSD834F2-15J STMicroelectronics, PSD834F2-15J Datasheet - Page 33

• Manufacturer Part Number: PSD834F2-15J
• Manufacturer: STMicroelectronics

Specifications of PSD834F2-15J

• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Package Type: PLCC
• Mounting: Surface Mount
• Pin Count: 52
• Lead Free Status / RoHS Status: Compliant

Product Term Allocator
The CPLD has a Product Term Allocator. The PS-
Dabel compiler uses the Product Term Allocator to
borrow and place product terms from one macro-
cell to another. The following 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.
If an equation requires more product terms than
are available to it, then “external” product terms
are required, which consume other Output Macro-
cells (OMC). If external product terms are used,
extra delay is added for the equation that required
the extra product terms.
McellAB0-McellAB7 all have three native
product terms and may borrow up to six more
McellBC0-McellBC3 all have four native product
terms and may borrow up to five more
McellBC4-McellBC7 all have four native product
terms and may borrow up to six more.
This is called product term expansion. PSDsoft
Express performs this expansion as needed.
Loading and Reading the Output Macrocells
(OMC). The Output Macrocells (OMC) block oc-
cupies a memory location in the MCU address
space, as defined by the CSIOP block (see the
section entitled “I/O PORTS”, on page 46). The
flip-flops in each of the 16 Output Macrocells
(OMC) can be loaded from the data bus by a MCU.
Loading the Output Macrocells (OMC) with data
from the MCU takes priority over internal func-
tions. As such, the preset, clear, and clock inputs
to the flip-flop can be overridden by the MCU. 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 can be loaded to the Output Macrocells
(OMC) on the trailing edge of Write Strobe (WR,
CNTL0) (edge loading) or during the time that
Write Strobe (WR, CNTL0) is active (level load-
ing). The method of loading is specified in PSDsoft
Express Configuration.
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