CSCI 255, ENGR 274, ECE 212 -- 28 November, 2000

Announcements

For the mathematician and linquistist
ε	the empty string
`x`	the symbol `x`
α β	The RE α followed by the RE β
α \| β	Either α or β
α^*	Zero or more sequences of α
(α)	α grouped
Examples include
(0\|1)*0	All even binary numbers
1010(0\|1)*	All binary numbers containing at least two 0's
(0\|1)111(0\|1)	All binary numbers that contain the sequence "111" somewhere in the number
For the Unix guru using grep, ed, sed, ...
`x`	Matches the non-special character. The characters '`?`', '`\`', '`.`', '`[`', '`]`', '`^`', '`$`', '`*`', '`(`', and '`)`'. are special
`[aeiou]`	Matches characters inside the brackets.
`[0-9A-F]`	Matches a range of characters.
`.`	Matches any character
`PATTERN`*	Matches a `PATTERN` occuring zero or more times.
`PATTERN`+	Matches a `PATTERN` occuring one or more times.
`PATTERN`?	Matches a `PATTERN` occuring zero or one time.
For the Perl programmer

See the Programmable Logic FAQ of Steve Knapp for up-to-date information.

Macrocells: Replicated collections of logic gates
perhaps a PLA and flip-flop
Interconnection: Means of connecting macrocells
in general, more macrocells implies less general connectivitiy
Programmability: Fuses, EPROM, SRAM, in-circuit

Few devices and lots of interconnect
Examples include
- PAL -- Programmable Array Logic
- PLA -- Programmable Logic Array
- GAL -- Generic Array Logic
Typical structure includes
- inputs
- AND plane to compute products
- OR plane to compute sums
- an XOR to invert the output
- a flip-flop to hold the output
  - generally called a registered output
- output multiplexers
Examples include
- Texas Instruments EPIC
- Cypress PLDC20G10B
More than you need for a simple sequential circuit

Abstract CPLD taken taken from Programmable Logic FAQ

Altera MAX 3000A block diagrams taken from 3000A Data Sheet

Likely structure
- Logic blocks with several macrocells
  - Similar to a SPLD
- I/O control blocks
- Interconnection switch or matrix
You can not program this by hand
Altera MAX 3000A datasheet
Properties of the Altera 3000 macrocell
- Five product terms, but
  - Sixteen shared expanders per local array
  - Up to fifteen parallel expanders from nieghboring macrocells
- Product term select matrix, for
  - OR and XOR gates
  - register controls
  - expander product terms