Lattice Semiconductor
ispMACH 4000V/B/C Family Data Sheet
8
Output Routing Pool (ORP)
The Output Routing Pool allows macrocell outputs to be connected to any of several I/O cells within an I/O block.
This provides greater
fl
exibility in determining the pinout and allows design changes to occur without affecting the
pinout. The output routing pool also provides a parallel capability for routing macrocell-level OE product terms. This
allows the OE product term to follow the macrocell output as it is switched between I/O cells. Additionally, the out-
put routing pool allows the macrocell output or true and complement forms of the 5-PT bypass signal to bypass the
output routing multipliers and feed the I/O cell directly. The enhanced ORP of the ispMACH 4000 family consists of
the following elements:
Output Routing Multiplexers
OE Routing Multiplexers
Output Routing Pool Bypass Multiplexers
Figure 7 shows the structure of the ORP from the I/O cell perspective. This is referred to as an ORP slice. Each
ORP has as many ORP slices as there are I/O cells in the corresponding I/O block.
Figure 7. ORP Slice
Output Routing Multiplexers
The details of connections between the macrocells and the I/O cells vary across devices and within a device
dependent on the maximum number of I/Os available. Tables 5, 6, 7 and 8 provide the connection details.
Table 5. ORP Combinations for I/O Blocks with 8 I/Os
I/O Cell
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
Available Macrocells
M0, M1, M2, M3, M4, M5, M6, M7
M2, M3, M4, M5, M6, M7, M8, M9
M4, M5, M6, M7, M8, M9, M10, M11
M6, M7, M8, M9, M10, M11, M12, M13
M8, M9, M10, M11, M12, M13, M14, M15
M10, M11, M12, M13, M14, M15, M0, M1
M12, M13, M14, M15, M0, M1, M2, M3
M14, M15, M0, M1, M2, M3, M4, M5
Output Routing Multiplexer
OE Routing Multiplexer
ORP
Bypass
Multiplexer
From Macrocell
From PTOE
To I/O
Cell
To I/O
Cell
Output
OE
5-PT Fast Path