Datasheet

233
ATtiny828 [DATASHEET]
8371A–AVR–08/12
Signals are described in Table 96, below. Pins not listed in the table are referenced by pin names.
Table 96. Pin and Signal Names Used in Programming Mode
Note: V
CC
- 0.3V < AV
CC
< V
CC
+ 0.3V, however, AV
CC
should always be within 4.5 – 5.5.
Pulses are assumed to be at least 250 ns, unless otherwise noted.
Table 97. Pin Values Used to Enter Programming Mode
Pins XA1 and XA0 determine the action when CLKI is given a positive pulse, as shown in Table 98.
Signal Name Pin(s) I/O Function
RDY/BSY PC0 O
0: Device is busy programming,
1: Device is ready for new command
OE PC1 I Output enable (active low)
WR PC2 I Write pulse (active low)
BS1 PC3 I Byte select 1 (0: low byte, 1: high byte)
XA0 PA0 I XTAL action bit 0
XA1 PA1 I XTAL action bit 1
BS2 PB6 I Byte Select 2 (0: low byte, 1: 2
nd
high byte)
PAGEL PA2 I Program memory and EEPROM data page load
DATA I/O
PB5 (MSB)
PB4
PB0
PA7
PA6
PA5
PA4
PA3 (LSB)
I/O Bi-directional data bus. Output when OE is low
Pin Symbol Value
PAGEL Prog_enable[3] 0
XA1 Prog_enable[2] 0
XA0 Prog_enable[1] 0
BS1 Prog_enable[0] 0