ATMEGA8L ATMEL [ATMEL Corporation], ATMEGA8L Datasheet - Page 222

• Manufacturer Part Number: ATMEGA8L
• Description: 8-bit AVR with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Parallel Programming
Parameters, Pin
Mapping, and
Commands
Signal Names
222
ATmega8(L)
This section describes how to parallel program and verify Flash Program memory,
EEPROM Data memory, Memory Lock Bits, and Fuse Bits in the ATmega8. Pulses are
assumed to be at least 250 ns unless otherwise noted.
In this section, some pins of the ATmega8 are referenced by signal names describing
their functionality during parallel programming, see Figure 104 and Table 89. Pins not
described in the following table are referenced by pin names.
The XA1/XA0 pins determine the action executed when the XTAL1 pin is given a posi-
tive pulse. The bit coding is shown in Table 91.
When pulsing WR or OE, the command loaded determines the action executed. The dif-
ferent Commands are shown in Table 92.
Figure 104. Parallel Programming
Table 89. Pin Name Mapping
Signal Name in
Programming Mode
RDY/BSY
OE
WR
BS1
XA0
XA1
RDY/BSY
PAGEL
+12 V
BS2
BS1
XA0
XA1
WR
Pin Name
OE
PD1
PD2
PD3
PD4
PD5
PD6
PD1
PD2
PD3
PD4
PD5
PD6
RESET
XTAL1
GND
PD7
PC2
PC[1:0]:PB[5:0]
I/O
O
I
I
I
I
I
Function
0: Device is busy programming, 1: Device
is ready for new command
Output Enable (Active low)
Write Pulse (Active low)
Byte Select 1 (“0” selects Low byte, “1”
selects High byte)
XTAL Action Bit 0
XTAL Action Bit 1
AVCC
VCC
+5V
+5V
DATA
2486M–AVR–12/03