PEEL22CV10AZ ETC, PEEL22CV10AZ Datasheet - Page 4

• Manufacturer Part Number: PEEL22CV10AZ
• Description: CMOS Programmable Electrically Erasable Logic Device
• Manufacturer: ETC

Anachip Corp.
www.anachip.com.tw
In addition to emulating the four PAL-type output structures
(configurations 3, 4, 9, and 10), The macrocell provides eight
additional configurations. Equivalent circuits for the twelve mac-
rocell configurations are illustrated in Figure 22. These structures
are
PEEL™22CV10A++ option when assembling the equations.
Figure 21 Equivalent Circuits for the Four Con-
figurations of the I/O Macrocell
Table 1. PEEL™22CV10A Macrocell
Configuration Bits
When creating a PEEL™ device design, the desired macrocell
configuration is generally specified explicitly in the design file.
When the design is assembled or compiled, the macrocell config-
uration bits are defined in the last lines of the JEDEC program-
ming file.
Output Type
The signal from the OR array can be fed directly to the output pin
(combinatorial function) or latched in the D-type flip-flop (regis-
tered function). The D-type flip-flop latches data on the rising
edge of the clock and is controlled by the global preset and clear
terms. When the synchronous preset term is satisfied, the Q out-
put of the register is set HIGH at the next rising edge of the clock
input. Satisfying the asynchronous clear sets Q LOW, regardless of
the clock state. If both terms are satisfied simultaneously, the clear
will override the preset.
Configuration
#
1
2
3
4
accessed
A
0
1
0
B
0
0
1
by
Input/Feedback
Bi-Directional
specifying
Feedback
Register
Select
I/O
the
Combinatorial
PEEL™22CV10A+
Register
Output Select
Active High
Active High
Active Low
Active Low
or
4/10
Output Polarity
Each macrocell can be configured to implement active-high or
active-low logic. Programmable polarity eliminates the need for
external inverters.
Output Enable
The output of each I/O macrocell can be enabled or disabled
under the control of its associated programmable output enable
product term. When the logical conditions programmed on the
output enable term are satisfied, the output signal is propagated to
the I/O pin. Otherwise, the output buffer is switched into the
high-impedance state.
Under the control of the output enable term, the I/O pin can func-
tion as a dedicated input, a dedicated output, or a bi-directional I/ O.
Opening every connection on the output enable term will per-
manently enable the output buffer and yield a dedicated output.
Conversely, if every connection is intact, the enable term will
always be logically false and the I/O will function as a dedicated
input.
Input/Feedback Select
When configuring an I/O macrocell to implement a registered
function (configurations 1 and 2 in Figure 21), the Q output of the
flip-flop drives the feedback term. When configuring an I/O mac-
rocell to implement a combinatorial output (configurations 3 and
4 in Figure 21), the feedback term is taken from the I/O pin. In this
case, the pin can be used as a dedicated input or a bi-direc- tional
I/O (Refer also to Table 1.)
Programmable Clock Options
A unique feature of the PEEL™22CV10AZ is a programmable
clock multiplexer that allows you to select true or complement
forms of either the input pin or a product-term clock source. This
feature can be accessed by specifying the PEEL™22CV10A++
option when assembling the equations.
Rev. 1.0 Dec 16, 2004