Rainbow Electronics Atmega169L - Manual (Page 269)

269
ATmega169V/L
2514A–AVR–08/02
Table 121. Pin Name Mapping
Signal Name in
Programming Mode Pin Name I/O Function
RDY/BSY PD1 O
0: Device is busy programming, 1: Device is ready
for new command.
OE PD2 I Output Enable (Active low).
WR PD3 I Write Pulse (Active low).
BS1 PD4 I
Byte Select 1 (“0” selects low byte, “1” selects
high byte).
XA0 PD5 I XTAL Action Bit 0
XA1 PD6 I XTAL Action Bit 1
PAGEL PD7 I Program Memory and EEPROM data Page Load.
BS2 PA0 I
Byte Select 2 (“0” selects low byte, “1” selects
2’nd high byte).
DATA PB7-0 I/O Bi-directional Data bus (Output when OE is low).
Table 122. Pin Values Used to Enter Programming Mode
Pin Symbol Value
PAGEL Prog_enable[3] 0
XA1 Prog_enable[2] 0
XA0 Prog_enable[1] 0
BS1 Prog_enable[0] 0
Table 123. XA1 and XA0 Coding
XA1 XA0 Action when XTAL1 is Pulsed
0 0 Load Flash or EEPROM Address (High or low address byte
determined by BS1).
0 1 Load Data (High or Low data byte for Flash determined by BS1).
1 0 Load Command
1 1 No Action, Idle