ADuCM310 Hardware Reference Manual
UG-549
Rev. C | Page 185 of 192
PROGRAMMABLE LOGIC ARRAY (PLA)
PLA FEATURES
The
integrates a fully programmable logic array (PLA) that consists of four independent but interconnected PLA blocks.
Each block consists of eight PLA elements: Block x Element 0 to Block x Element 7, where x is the block number. Each
4 blocks, giving a total of 32 PLA elements: Element 0 to Element 31.
PLA OVERVIEW
Each PLA element contains a two-input lookup table that can be configured to generate any logic output function based on two inputs
and a flip-flop.
4
2
0
A
B
LOOKUP
TABLE
3
1
PLA_ELEMn[4:1]
PLA_ELEMn[5]
PLA_ELEMn[10:9]
PLA_ELEMn[8:7]
GPIO INPUT
PLA_ELEMn[6]
PLA_DIN0[n]
2
PLA_ELEMn[0]
PLA_CLK
1
THE FIRST SELECTION OF MUX0 IS THE FEEDBACK FROM BLOCK x ELEMENT 0, WHERE x IS THE NUMBER OF THE CURRENT BLOCK.
IF THE FIRST ELEMENT IN THE BLOCK IS BEING CONFIGURED, THE FEEDBACK COMES FROM ANOTHER BLOCK.
SEE THE INTERBLOCK CONNECTION DIAGRAM FOR MORE DETAILS.
2
FOR BLOCK 0 AND BLOCK 1 IS SET IN THE CORRESPONDING BIT IN THE PLA_DIN0 MMR.
BLOCK x ELEMENT 1
BLOCK x ELEMENT 3
BLOCK x ELEMENT 5
BLOCK x ELEMENT 7
OUTPUT ELEMENT n
WHERE:
BLOCK x IS BLOCK 0 OR BLOCK 1
PLA_ELEMn IS THE MMR CONTROLLING ELEMENT n, n = 0 TO 15
NC = NO CONNECTION
BLOCK x ELEMENT 0
BLOCK x ELEMENT 2
BLOCK x ELEMENT 4
BLOCK x ELEMENT 6
1
1
1461-
032
Figure 34. PLA Element: Block 0 and Block 1
4
2
0
A
B
LOOKUP
TABLE
3
1
PLA_ELEMn[4:1]
PLA_ELEMn[5]
PLA_ELEMn[10:9]
PLA_ELEMn[8:7]
NC
PLA_ELEMn[6]
OUTPUT ELEMENT (N – 16)
2
PLA_ELEMn[0]
PLA_CLK
BLOCK x ELEMENT 0
BLOCK x ELEMENT 2
BLOCK x ELEMENT 4
BLOCK x ELEMENT 6
1
BLOCK x ELEMENT 1
BLOCK x ELEMENT 3
BLOCK x ELEMENT 5
BLOCK x ELEMENT 7
OUTPUT ELEMENT n
WHERE:
BLOCK x IS BLOCK 2 OR BLOCK 3
PLA_ELEMn IS THE MMR CONTROLLING ELEMENT n, n = 16 TO 31
NC = NO CONNECTION
1
THE FIRST SELECTION OF MUX0 IS THE FEEDBACK FROM BLOCK x ELEMENT 0, WHERE x IS THE NUMBER OF THE CURRENT BLOCK.
IF THE FIRST ELEMENT IN THE BLOCK IS BEING CONFIGURED, THE FEEDBACK COMES FROM ANOTHER BLOCK.
SEE THE INTERBLOCK CONNECTION DIAGRAM.
2
FOR BLOCK 2 AND BLOCK 3, THE INPUT COMES FROM THE OUTPUT OF ELEMENT (n – 16),
WHERE n IS THE NUMBER OF THE ELEMENT BEING CONFIGURED. FOR EXAMPLE, FOR ELEMENT 25 THE INPUT TO MUX 2 COMES FROM
ELEMENT 9. THIS ALLOWS GPIO INPUTS TO BE INDIRECTLY CONNECTED TO ELEMENTS IN BLOCK 2 AND BLOCK 3.
1
1461-
033
Figure 35. PLA Element: Block 2 and Block 3