I/O Structures in IGLOO and ProASIC3 Devices
7- 32
v1.1
User I/O Naming Convention
IGLOO and ProASIC3
Due to the comprehensive and flexible nature of IGLOO and ProASIC3 device user I/Os, a naming
page 7-33). The name identifies to which I/O bank it belongs, as well as pairing and pin polarity for
differential I/Os.
I/O Nomenclature
= FF/Gmn/IOuxwBy
Gmn is only used for I/Os that also have CCC access—i.e., global pins.
FF
= Indicates the I/O dedicated for the Flash*Freeze mode activation pin in IGLOO and
ProASIC3L devices only
G= Global
m
= Global pin location associated with each CCC on the device: A (northwest corner), B
(northeast corner), C (east middle), D (southeast corner), E (southwest corner), and F (west
middle)
n
= Global input MUX and pin number of the associated Global location m—either A0, A1, A2,
information about the three input pins per clock source MUX at CCC location m.
u
= I/O pair number in the bank, starting at 00 from the northwest I/O bank and proceeding in a
clockwise direction
x
= P or U (Positive), N or V (Negative) for differential pairs, or R (Regular—single-ended) for
the I/Os that support single-ended and voltage-referenced I/O standards only. U (Positive) or
V (Negative)—for LVDS, DDR LVDS, BLVDS, and M-LVDS only—restricts the I/O differential
pair from being selected as an LVPECL pair.
w
= D (Differential Pair), P (Pair), or S (Single-Ended). D (Differential Pair) if both members of the
pair are bonded out to adjacent pins or are separated only by one GND or NC pin; P (Pair) if
both members of the pair are bonded out but do not meet the adjacency requirement; or S
(Single-Ended) if the I/O pair is not bonded out. For Differential Pairs (D), adjacency for ball
grid packages means only vertical or horizontal. Diagonal adjacency does not meet the
requirements for a true differential pair.
B
= Bank
y
= Bank number (0–3). The Bank number starts at 0 from the northwest I/O bank and proceeds
in a clockwise direction.