ATmega48PA/88PA

27.5Page Size

Table 27-8.

No. of Words in a Page and No. of Pages in the Flash

 

 

 

 

 

 

 

No. of

 

 

Device

 

Flash Size

Page Size

PCWORD

Pages

PCPAGE

PCMSB

 

 

 

 

 

 

 

 

ATmega48PA

 

2K words

32 words

PC[4:0]

64

PC[10:5]

10

 

(4K bytes)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ATmega88PA

 

4K words

32 words

PC[4:0]

128

PC[11:5]

11

 

(8K bytes)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 27-9.

No. of Words in a Page and No. of Pages in the EEPROM

 

 

 

EEPROM

Page

 

No. of

 

 

Device

 

Size

Size

PCWORD

Pages

PCPAGE

EEAMSB

 

 

 

 

 

 

 

 

ATmega48PA

 

256 bytes

4 bytes

EEA[1:0]

64

EEA[7:2]

7

 

 

 

 

 

 

 

 

ATmega88PA

 

512 bytes

4 bytes

EEA[1:0]

128

EEA[8:2]

8

 

 

 

 

 

 

 

 

27.6Parallel Programming Parameters, Pin Mapping, and Commands

This section describes how to parallel program and verify Flash Program memory, EEPROM Data memory, Memory Lock bits, and Fuse bits in the ATmega48PA/88PA. Pulses are assumed to be at least 250 ns unless otherwise noted.

27.6.1Signal Names

In this section, some pins of the ATmega48PA/88PA are referenced by signal names describing their functionality during parallel programming, see Figure 27-1 and Table 27-10. 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 positive pulse. The bit coding is shown in Table 27-12.

When pulsing WR or OE, the command loaded determines the action executed. The different Commands are shown in Table 27-13.

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ATmega48PA/88PA

Figure 27-1. Parallel Programming

 

 

 

 

 

 

 

 

 

 

+4.5 - 5.5V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RDY/BSY

 

 

 

 

PD1

VCC

 

 

 

 

 

 

OE

 

 

 

 

PD2

 

+4.5 - 5.5V

 

 

 

 

 

 

 

 

 

 

 

AVCC

 

 

 

 

 

 

WR

 

 

 

PD3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BS1

 

 

 

PD4

PC[1:0]:PB[5:0]

 

 

 

DATA

 

 

 

 

 

 

XA0

 

 

 

 

PD5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

XA1 PD6

PAGEL PD7

+12 V RESET

BS2 PC2

XTAL1

GND

Note: VCC - 0.3V < AVCC < VCC + 0.3V, however, AVCC should always be within 4.5 - 5.5V

Table 27-10. Pin Name Mapping

 

Signal Name in

 

 

 

 

 

 

Programming Mode

Pin Name

I/O

Function

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0: Device is busy programming, 1: Device is

 

 

RDY/BSY

PD1

O

 

 

ready for new command

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PD2

I

Output Enable (Active low)

 

 

OE

 

 

 

 

 

 

 

 

 

 

 

 

PD3

I

Write Pulse (Active low)

 

 

WR

 

 

 

 

 

 

 

 

 

 

 

 

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

PC2

I

Byte Select 2 (“0” selects Low byte, “1” selects

 

 

2’nd High byte)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DATA

{PC[1:0]: PB[5:0]}

I/O

Bi-directional Data bus (Output when

 

 

 

OE is low)

 

 

 

 

 

 

 

 

 

 

 

 

Table 27-11. 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

 

 

 

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