NASA Office of Logic Design

NASA Office of Logic Design

A scientific study of the problems of digital engineering for space flight systems,
with a view to their practical solution.

RT54SX-S Pin Incompatibilities

NOTE: PRELIMINARY; BEING CHECKED FOR TYPOS AND OMISSIONS

The following information is based on "RT54SX-S RadTolerant FPGAs for Space Applications," Advanced v0.2, March 2001.

Topics:

  1. Available Pins
  2. CQFP208: RT54SX32S vs. RT54SX72S
  3. CQFP256: RT54SX32S vs. RT54SX72S
  4. VCCR Incompatibility with RT54SX Series Devices
  5. Termination of Clock Pins

In moving from an RT54SX32S to an RT54SX72S there are 3 cases:

  1. I/O ® Power Connection {GND, VCCI ,VCCA}
  2. I/O ® {QCLK, I/O}
  3. NC ® I/O

 

1. Available Pins Per Device and Package

Device User I/Os (including clock buffers)
CQFP208 CQFP256
RT54SX32S 173 227
RT54SX72S 170 212
Loss 3 15

 

2. CQFP208: RT54SX32S vs. RT54SX72S

Package: CQFP08
Pin Number RT54SX32S Function RT54SX72S Function
18 I/O GND
19 I/O VCCA
25 NC I/O
65 NC I/O
74 I/O {QCLKA, I/O}
83 I/O VCCI
84 I/O {QCLKB, I/O}
116 I/O GND
117 I/O VCCA
132 NC I/O
178 I/O {QCLKD, I/O}
187 I/O VCCI
190 I/O {QCLKC, I/O}

 

3. CQFP256: RT54SX32S vs. RT54SX72S

Package: CQFP256
Pin Number RT54SX32S Function RT54SX72S Function
17 I/O VCCI
36 I/O VCCA
37 I/O GND
47 I/O VCCI
56 I/O GND
73 I/O VCCI
89 I/O {QCLKA, I/O}
98 I/O {QCLKB, I/O}
120 I/O VCCI
142 I/O VCCI
143 I/O GND
144 I/O VCCA
162 I/O VCCA
183 I/O VCCI
202 I/O VCCI
218 I/O {QCLKD, I/O}
228 I/O VCCA
231 I/O {QCLKC, I/O}
249 I/O VCCI

 

4. RT54SXS Incompatibility with VCCR of the RT54SX Series

Note: In moving from an RT54SX to an RT54SXS, the VCCR supply is not used in the RT54SXS series.  On the RT54SX32S it is a NC.  For the RT54SX72S in the CQFP208 package, there are two incompatibilities.

VCCR Usage in the RT54SX Series and Mapping onto Functions in the RT54SXS Series Devices
  RT54SX VCCR RT54SX32S RT54SX72S
CQFP208 25 NC I/O
80 NC NC
132 NC I/O
182 NC NC
CQFP256 159 NC NC
223 NC NC

 

5. Termination of Clock Pins

This is handled a bit differently in each of the SX and SXS devices.  See separate application note.  I shall supply a link here later.

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Last Revised: November 01, 2003
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