ATmega16A

26.5Page Size

Table 26-5.

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

 

 

 

 

Flash Size

 

Page Size

PCWORD

 

No. of Pages

 

PCPAGE

PCMSB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8K words (16K bytes)

 

64 words

 

PC[5:0]

 

128

 

 

PC[12:6]

12

 

 

 

 

 

 

 

 

 

 

 

 

Table 26-6.

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

 

 

 

 

 

 

 

 

 

 

 

 

EEPROM Size

 

Page Size

 

PCWORD

 

No. of Pages

 

PCPAGE

 

EEAMSB

 

 

 

 

 

 

 

 

 

 

 

 

512 bytes

 

 

4 bytes

 

EEA[1:0]

 

128

 

EEA[8:2]

 

8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

26.6Parallel 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 ATmega16A. Pulses are assumed to be at least 250 ns unless otherwise noted.

26.6.1Signal Names

In this section, some pins of the ATmega16A are referenced by signal names describing their functionality during parallel programming, see Figure 26-1 and Table 26-7. 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 26-9.

When pulsing WR or OE, the command loaded determines the action executed. The different Commands are shown in Table 26-10.

Figure 26-1. Parallel Programming

 

 

 

 

 

 

 

 

 

 

 

+5V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RDY/BSY

 

 

 

 

PD1

VCC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5V

 

 

 

 

 

 

 

 

 

 

 

 

OE

 

PD2

 

 

 

 

 

 

 

 

 

 

 

 

WR

 

 

 

 

PD3

AVCC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BS1

 

 

 

PD4

PB7 - PB0

 

 

 

DATA

 

 

 

 

 

 

XA0

 

 

 

 

PD5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

XA1 PD6

PAGEL PD7

+12 V RESET

BS2 PA0

XTAL1

GND

267

8154A–AVR–06/08

Table 26-7. Pin Name Mapping

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Signal Name in

 

 

 

 

 

 

 

 

 

 

 

Programming Mode

Pin Name

 

 

I/O

Function

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0: Device is busy programming, 1: Device is ready for

 

 

RDY/BSY

PD1

 

 

O

 

 

 

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

PA0

 

 

I

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

 

 

 

 

High byte)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DATA

PB7-0

 

 

I/O

Bidirectional Data bus (Output when

 

is low)

 

 

OE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 26-8. 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 26-9. 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

 

 

 

Table 26-10. Command Byte Bit Coding

Command Byte

Command Executed

 

 

1000 0000

Chip Erase

 

 

0100 0000

Write Fuse Bits

 

 

0010 0000

Write Lock Bits

 

 

0001 0000

Write Flash

 

 

0001 0001

Write EEPROM

 

 

268 ATmega16A

8154A–AVR–06/08

Соседние файлы в папке МК