Operation mode, 1 flash products, 1 switch configuration – Atmel C51 User Manual
Page 13: 2 running isp, Section 3 operation mode -10, Flash products -10, Switch configuration -10, Running isp -10

Operation Mode
C51 Microcontrollers Demo Board User Guide
3-10
4119C–8051–3/03
Section 3
Operation Mode
3.1
Flash Products
3.1.1
Switch
Configuration
To program the on-chip Flash memory, hardware configuration of the chip should be the
following: PSEN = 0, EA = 1 and ALE = 1 or not connected.
On C51/C251 Demo Board, switches must be as shown on Figure 3-2.
Figure 3-1. C51/C251 Demo Board Switches Configuration to use ISP
3.1.2
Running ISP
The C51/C251 Demo Board must be connected to a PC com port via the RS232 cable
connected to the RS232 connector of C51/C251 Demo Board.
After downloading, you can run code by switching PSEN on J11 to 1 and pressing the
RESET push button.
J11
PSEN
ALE
ISP1
U
s
er
C
ode
1
0
1
0
J11
J9
J16
J9
J16
EA
MAP SELECT
ISP2
RS232 Cable to PC
Position don’t care
Position needed