EVB_1A2 & EVB_1A3 Details This board supports the CPU_1A1 module for development, experimentation and programming.
INTRODUCTION This page provides information on configuting and operating the EVB boards. Once you're familiar with the CPU_1A1 and the HC11 boot loader, the EVB operation will be fairly obvious. There are currently 2 versions, EVB_1A2 (version 2) and EVB_1A3 (version 3). Version 1 was a prototype only. Version 2 consisted of only about 30 boards. Version 3 is due for release in July 1999. The demand for the EVB boards has been low because most CPU_1A1 applications include the features provided by the EVB in the product itself. The EVB is usefull for testing and pre-loading code.
Operation - Features - Kitset - Downloads
EVB_1A2 (version 2)	EVB_1A3 (version 3)
The grey bits explained Version 2 The CPU_1A1 module is turned on & off by inserting or removing the link LK2 shown just below the CPU_1A1 module itself. This is used to reset the CPU. 12V (or the supply voltage) is not available on the end terminal of P103 (screw terminal). Version 3 The on/off switch replaces link LK2 (version 2) for resetting the CPU. 12V (or the supply voltage) is available on the end terminal of P103 (screw terminal). Both Versions The links LK1 send RS-232 or 5V CMOS levels to the 9 pin D connector. For normal operation the links should be set for RS-232 (the grey marked position). The CPU_1A1 must be inserted into the socket with the components facing the 9 pin D connector. Reversal could damage the CPU_1A1. OPERATING INSTRUCTIONS Connect the EVB to a PC serial Com port using a standard straight serial cable. Remove link LK2 (version 2) or turn switch off (version 3). Connect power to the EVB (center pin is +ve). Insert the CPU_1A1 module, ensuring correct orientation (components facing D connector). Should the mode links be inserted on the CPU_1A1 (it depends on what you're doing) ???? Insert LK2 or switch on to power up the CPU_1A1 Load or run your program. NOTES - HINTS Do not leave the the CPU_1A1 powered up for extended periods without a program loaded or running. When first reset into bootstrap mode, the address decoding is undefined. The memory chips will run warm because they are not in a well defined low power state. This does not affect nornal operation. Remember to reset the CPU_1A1 (LK2 or switch) before reloading your program. It's a good idea to link an LED to a the CPU_1A1 on the EVB. With a few lines added to your program, you can easilly identify whats going on, or what progress is. For the demo programs, link pin 2 to pin 33. FEATURES Onboard 5 Volt power supply from a 9V to 18V DC input One RS-232 port (9 pin D) Prototype area with pins for wire-wrap linking Four push buttons and three LED indicators Six screw terminals for I/O connections Resistors providing some protection to the CPU_1A1 from the prototyping area. The CPU_1A1 module plugs into a 25 way socket on the board Size = 120 mm by 85 mm (approx) The EVB is supplied less power source, serial cable and CPU_1A1 module. To make use of the board, a 12V DC plug-pack or bench supply, 9 pin male to PC serial cable and a CPU_1A1 module will be required. A small wire-wrap hand tool and wire are required to use the prototype area. KITSET DETAILS The EVB can be supplied fully assembled, in kit form or as a PCB only. A parts list follows. Most of the parts are readilly available. The socket for the CPU_1A1 may be a challenge. You can use smaller end stackable sections ie. 10 + 10 + 5. Be carefull, nat all of the cheaper ones are stackable without loosing the 0.1 inch pitch.

Qty.	Description	Specifics / notes	Source
1	PCB	EVB_1A3	PMB Electronics
1	9 pin D, right angle, female	.	.
1	DC socket, 1.5mm pcb mount	.	Farnell, 224-959
2	3 pole screw terminal block	.	.
1	25 way, single row, PCB socket, vertical	.	.
39	pin header, single row	25 & 6 & 8.	.
8	pin header, double row	4 by 2	.
2	jumpers (mini shunt)	0.1 inch pitch	.
4	mini push buttons	.	.
1	switch, pcb mount, verticle, toggle or push	on/off	.
1	PTC resettable fuse, 0.12Amp	0.2 inch	.
1	MAX232CPE	palstic DIP.	.
1	7805CT, voltage regulator	TO-220	.
3	LED (any colour)	3mm	.
1	1N4004 diode	supply reverse pol. protect	.
1	33V 1W zener diode	supply spike suppression	.
1	100uF 25V capacitor	0.1 inch	.
2	22uF 16V capacitor (10uF to 33uF will do)	0.1 inch	.
4	10uF 16V tantalum capacitor	0.1 inch	.
5	0.1uF monolythic capacitor	0.2 inch	.
2	0R link	.	.
29	1K 0.25W 5% carbon resistor	.	.
1	10K 0.25W 5% carbon resistor	.	.
.	.	.	.
.	.	.	.

Files available for Download
EVB Circuit Diagram (pdf)	CPU_1A1 Circuit Diagram (pdf)	.
.	.	.

NOTES: PMB can provide some support to users of the CPU_1A1. Numbering system CPU_1A1. "CPU_1" describes the product, "A" describes the board or module within the product, "1" describes the revision. Items are available under PMB standard terms and conditions of sale.

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last updated: 16 Jan 2004