User Manual

1.7 Reconfiguring the 7521(D)/7522(D)/7523(D)
From pin-4 to pin-8 of the 7521/7522/7523 there are three D/O & two D/I
pins. For the application of “Customized 7000 Modules”, these 5 D/I/O pins
can be hardware reconfigured to other functions as follows:
Step 1: Remove the reconfiguration-resistor as follows:
 If DO3 is reconfigured, remove R19
 If DO2 is reconfigured, remove R20
 If DO1 is reconfigured, remove R21
 If DI3 is reconfigured, remove R22
 If DI2 is reconfigured, remove R23
Then, the onboard D/I/O functions can be disabled.
Step 2: Install a 5-pin male reconfiguration-jumper into the TP0 of the
7521(D)/7522(D)/7523(D)
Step 3: Design a 5-pin female reconfiguration-jumper in X??? for
connection to TP1. Then the external signals from pin-4 to pin-8
can be connected to X???. The user can refigure these 5 D/I/O pins
to their special requirements now.
Note: If the DO2 is reconfigured to D/I, its initial state must be High. If its
initial state is LOW, system clock will be reduced to 10M. So all
clock-related libraries will only be at half-speed.
The X100 is an 8-channel D/I board designed for the 7521/7522/7523. It
removes all 5 resistors, R19 ~ R23, and reconfigures all these pins as D/I pins.
It installs another 5-pin female reconfiguration-jumper into TP1 of the
7521/7522/7523.
Therefore, user can select the original 3_DO_2_DI functions or new
5_DI functions by setting the jumper in different positions. Refer to “I/O
Expansion Bus in the 7188X/7188E User’s Manual” for more information.
The user-defined pins of the 7521 family are given as follows:
User defined pins Reconfiguration pins Customized I/O pins
7521(D) 3 5 3+5=8
7522(D)/7522A(D)/
7523(D)/7524(D)/
7527(D)
0 0 0+0=0
7521/2/2A/3/4/7 Series Hardware User’s Manual, Ver. 1.5 Sep/2002, 7Mh-001-15 -----43