Obsolete
Product(s)
- Obsolete
Product(s)
PLDs
UPSD3254A, UPSD3254BV, UPSD3253B, UPSD3253BV
The Input Macrocells (IMC) and Output Macrocells (OMC) are connected to the PSD
module internal data bus and can be directly accessed by the MCU. This enables the MCU
software to load data into the Output Macrocells (OMC) or read data from both the Input and
Output Macrocells (IMC and OMC).
This feature allows efficient implementation of system logic and eliminates the need to
connect the data bus to the AND Array as required in most standard PLD macrocell
architectures.
Figure 58.
Macrocell and I/O ports
23.4
Output macrocell (OMC)
Eight of the Output Macrocells (OMC) are connected to Ports A and B pins and are named
as McellAB0-McellAB7. The other eight macrocells are connected to Ports B and C pins and
are named as McellBC0-McellBC7. If an McellAB output is not assigned to a specific pin in
PSDsoft, the Macrocell Allocator block assigns it to either Port A or B. The same is true for a
McellBC output on Port B or C.
Table 92 shows the macrocells and port assignment.
The Output Macrocell (OMC) architecture is shown in
Figure 59. As shown in the figure,
there are native product terms available from the AND Array, and borrowed product terms
available (if unused) from other Output Macrocells (OMC). The polarity of the product term
is controlled by the XOR gate. The Output Macrocell (OMC) can implement either sequential
logic, using the flip-flop element, or combinatorial logic. The multiplexer selects between the
sequential or combinatorial logic outputs. The multiplexer output can drive a port pin and
has a feedback path to the AND Array inputs.
The flip-flop in the Output Macrocell (OMC) block can be configured as a D, T, JK, or SR
type in PSDsoft. The flip-flop’s clock, preset, and clear inputs may be driven from a product
term of the AND Array. Alternatively, CLKIN (PD1) can be used for the clock input to the flip-
I/O PORTS
CPLD MACROCELLS
INPUT MACROCELLS
LATCHED
ADDRESS OUT
MUX
D
Q
G
D
QD
WR
PDR
DATA
PRODUCT TERM
ALLOCATOR
DIR
REG.
SELECT
INPUT
PRODUCT TERMS
FROM OTHER
MACROCELLS
POLARITY
SELECT
UP TO 10
PRODUCT TERMS
CLOCK
SELECT
PR
DI LD
D/T
CK
CL
Q
D/T/JK FF
SELECT
PT CLEAR
PT
CLOCK
GLOBAL
CLOCK
PT OUTPUT ENABLE (OE)
MACROCELL FEEDBACK
I/O PORT INPUT
ALE
PT INPUT LATCH GATE/CLOCK
MCU LOAD
PT PRESET
MCU DATA IN
COMB.
/REG
SELECT
MACROCELL
TO
I/O PORT
ALLOC.
CPLD
OUTPUT
TO OTHER I/O PORTS
PLD
INPUT
BUS
PLD
INPUT
BUS
MCU ADDRESS / DATA BUS
MACROCELL
OUT TO
MCU
DATA
LOAD
CONTROL
AND
ARRAY
CPLD OUTPUT
I/O PIN
AI06602