by development software to verify the design and create a programming file. This file, once
downloaded to a programmer, configures the device according to the user’s desired function.
The user is given two design options with the PALCE20V8. First, it can be programmed as an
emulated PAL device. This includes the PAL20R8 series and most 24-pin combinatorial PAL
devices. The PAL device programmer manufacturer will supply device codes for the standard
PAL architectures to be used with the PALCE20V8. The programmer will program the PALCE20V8
to the corresponding PAL device architecture. This allows the user to use existing standard PAL
device JEDEC files without making any changes to them. Alternatively, the device can be
programmed directly as a PALCE20V8. Here the user must use the PALCE20V8 device code. This
option provides full utilization of the macrocells, allowing non-standard architectures to be built.
To
Adjacent
Macrocell
11
0X
10
OE
V
CC
11
10
00
01
SL0
X
SG1
11
0X
D
SL1
X
CLK
Q
Q
10
11
0X
*SG1
*In macrocells MC
0
and MC
7
, SG1 is replaced by SG0 on the feedback multiplexer.
16491E
I/O
X
10
SL0
X
From
Adjacent
Pin
Figure 1. PALCE20V8 Macrocell
PALCE20V8 Family
3
LATTICE [ LATTICE SEMICONDUCTOR ]
