Board Applications
9-4
STK200 Starter Kit
Analog Port: Marked on Board
The A/D converters can use either the on-board (Internal) Voltage Reference or an
external Voltage Reference.
9.4.1
Using Internal
Reference
To use the internal on-board Voltage Reference, the pot marked “AREF” is used to set
the voltage level. The voltage level can be measured with a meter connected to the
header pins labeled “Analog Ref” and “Analog Gnd” in the above diagram or from the
two holes marked “Meter +” and “Meter -”.
9.4.2
Using External
Reference
To use the A/D converters with an external Voltage Reference, the link marked “LK1”
must be cut. The voltage is applied to the pins marked “Analog Ref” and “Analog Gnd”
on the Analog header—see diagram above.
9.5
Using External
RAM
The AT90S8515 and AT90S4414 can be used with external SRAM. A socket is provided
for a 28-pin RAM chip and for an address latch chip. These are next to the Atmel logo on
the board.
9.5.1
RAM
Recommendations
A low-power 62256 SRAM is suggested with an access time of 70 ns. If a very fast RAM
is required, the crystal frequency may need to be increased. If a much slower SRAM is
used, the SRAM Wait State bit must be enabled in user software—see data book. The
layout of the 28-pin RAM socket is shown below, and any RAM with this pin-out could be
used.
RAM Socket pin layout
9.5.2
Address Latch
The board connections are for a 74HC573 device. This device will operate reliably with
the 4 MHz crystal supplied but if a faster crystal is inserted, a faster version of this
device may be required—74AHC573 or 74FHC573. Note that this option will alter the
EMC characteristics of the board and the CE mark will no longer be valid without retest-
ing.
CUT OUT MARKED
ON BOARD
FOR ORIENTATION
NOT CONNECTED ON
28-PIN SOCKET
40-PIN DEVICES
ADC0 - ADC7 CONNECTED TO PORT A
PA0 - PA7
28-PIN DEVICES
ADC0 - ADC5 CONNECTED TO PORT C
PC0 - PC5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
VSS
VCC
WE
A13
A8
A9
A11
OE
A10
CS
I/O7
I/O6
I/O5
I/O4
I/O3
Summary of Contents for STK200
Page 4: ...Table of Contents iv...
Page 6: ...Introduction 1 2 STK200 Starter Kit...
Page 8: ...Getting Started 2 2 STK200 Starter Kit...
Page 10: ...Connecting the Hardware 3 2 STK200 Starter Kit...
Page 14: ...Installing the Software 5 2 STK200 Starter Kit...
Page 22: ...How to use the Software 6 8 STK200 Starter Kit...
Page 26: ...Brown Out Detector 8 2 STK200 Starter Kit...
Page 36: ...Technical Support 11 2 STK200 Starter Kit...
Page 38: ...Appendix II Warranty Statement 12 2 STK200 Starter Kit...
Page 39: ...Appendix II Warranty Statement STK200 Starter Kit 12 3...
