atmega161-4pi ATMEL Corporation, atmega161-4pi Datasheet - Page 118

• Manufacturer Part Number: atmega161-4pi
• Description: 8-bit Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Parallel Programming
Signal Names
118
ATmega161(L)
This section describes how to parallel program and verify Flash Program memory,
EEPROM Data memory, Lock bits and Fuse bits in the ATmega161. Pulses are
assumed to be at least 500 ns unless otherwise noted.
In this section, some pins of the ATmega161 are referenced by signal names describing
their functionality during parallel programming (see Figure 75 and Table 42). Pins not
described in the following table are referenced by pin name.
The XA1/XA0 pins determine the action executed when the XTAL1 pin is given a posi-
tive pulse. The bit codings are shown in Table 43.
When pulsing WR or OE, the command loaded determines the action executed. The
command is a byte where the different bits are assigned functions as shown in Table 44.
Figure 75. Parallel Programming
Table 42. Pin Name Mapping
Programming Mode
Signal Name in
RDY/BSY
BS1
XA0
XA1
WR
OE
RDY/BSY
PAGEL
+12 V
BS1
XA0
XA1
WR
OE
Pin Name
PD1
PD2
PD3
PD4
PD5
PD6
PD1
PD2
PD3
PD4
PD5
PD6
PD7
RESET
XTAL1
GND
PA0
I/O
O
I
I
I
I
I
ATmega161
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
PB7 - PB0
VCC
+5V
DATA
1228D–AVR–02/07