Answers Database

Differences between 4000ex and 5200 express mode?


Record #1522

Problem Title:
Differences between 4000ex and 5200 express mode?


Problem Description:
Keywords: express mode, 4000ex, 5200

Urgency: Standard

General Description:  What are the differences between
4000ex and 5200 configured for express mode?


Solution 1:

First, reference pg 4-200 (9/96 data book) concerning
5200 Express Mode and 4-76 (9/96 data book) concerning
4000ex Express Mode.

Express mode is similar to Slave Serial mode for both
devices.  However, in Express the data is processed
1 byte per CCLK cycle rather than 1 bit CCLK cycle.
The order of the byte is presented in the same fashion
as if the device were configured for Peripheral download
(please see solution 885 for more details).

In Express Mode, the *external* signals are identical
between 5200 and 4000ex.  However, internally there are
some differences.
1) 5200 Express uses a 21-bit length count (LC) value
   because of the byte-wide down-load.

   4000ex Express requires no LC because the device
   becomes active when DONE goes high.

2) Since there is a difference in LC values, the data
   streams are also different between the 2 devices.
   Please reference pg 4-56 (9/96 data book) concerning
   4000ex Data Stream Format and pg 4-202 (9/96 data book)
   concerning 5200 Data Stream Format.

   The Data Stream is the same for 5200 regardless of the
   configuration mode.	However, the Data Stream for
   4000ex is a different between Express and other modes
   of configuration.

3) The 5200 formats for Express and other modes are the
   same because the data shift register inside is all
   parallel.  In the 4000ex, the data shift register is
   divided into 8 segments and the data stream is all
   swaped around.

Currently for the 5200, as addressed on pg 4-200 (9/96
data book) "Bitsream generation currently generates a
bitstream sufficient for all modes except Express."
The workaround for this problem is described on pg 4-200.





End of Record #1522