Evaluation Kit User Manual for PIC Board

EV6000

© 1996 Consumer Microcircuits Limited

10

UM6000/3

1.6

Detailed Description

1.6.1

Hardware Description

1.6.1.1 Operating Voltage

The selection of operating voltage (VDD = 3.3V or 5.0V) by jumper JP1 affects the choice of

component values around the evaluation device on the EV6020 or EV6040 Evaluation Kit. Care should

be taken to ensure that JP1 is set the same way as jumpers JP1, JP3, JP4, JP5, JP6 and JP7 on the

EV6020 or EV6040 Evaluation Kit.

1.6.1.2 Clock/Oscillator

A 4MHz xtal is the highest frequency xtal that may be used with a PIC16LC74(A)JW at

VDD = 3.3V. The PIC 16C74(A)JW has a similar limitation and is fitted for availability reasons.

Although rated at 5.0V, it has been found to work successfully at 3.3V. Two jumpers JP2, which are

normally fitted, select an on-board 4MHz xtal. An external 3.58MHz clock, for example, may be

supplied to JP2_1 (1) once the jumpers have been removed, taking care to adjust any firmware timing

routines accordingly.

1.6.1.3 RS232 Interface

The RS232 interface (connector J3) has its communications protocol determined by the

µC firmware.

A suggested configuration is 8 data bits, no parity, 1 stop bit and 19,200 baud with hardware

handshake but without CR -> CR/LF conversion. Linefeeds are provided by the EV6000 firmware.

The firmware supplied in the PIC

µC assumes this configuration.

1.6.1.4 Programming Mode

TO ENTER PROGRAMMING MODE

(a) Remove power from board

(b) Disconnect the EV6000 from other Evaluation Kits

(c) Ensure jumper JP1 is fitted in position 2,3 for VDD = 5.0V

(d) Remove link on jumper JP3

(e) Insert links on jumpers JP4, JP5, JP6 and JP7

(f) Re-apply power to board

(g) Connect the programming voltage (VPP = 12.5V to 13.5V) power supply between test point

TP5 (+ve) and VSS (-ve)

(h) Ensure the PIC

µC programming utility PICPROGA.EXE is loaded into the PC under DOS

and the PC is connected to the evaluation kit

(i) Download firmware into the PIC

µC and verify it

TO LEAVE PROGRAMMING MODE

(a) Remove power from board (including the programming voltage)

(b) Remove links on jumpers JP4, JP5, JP6 and JP7

(c) Insert a link on jumper JP3

(d) Reconnect jumper JP1 in its original position

(e) Reconnect the EV6000 to the other Evaluation Kits, checking that the voltage selection

jumpers are correctly set

(f) Ensure the terminal emulator program is running on the PC

(g) Re-apply power to board and run

µC firmware via the PC terminal emulator