Rainbow-electronics Atmega169L Manuel d'utilisateur télécharger pdf (Page 281)

281

ATmega169V/L

2514A–AVR–08/02

Data Polling EEPROM When a new byte has been written and is being programmed into EEPROM, reading the

address location being programmed will give the value 0xFF. At the time the device is

ready for a new byte, the programmed value will read correctly. This is used to deter-

mine when the next byte can be written. This will not work for the value 0xFF, but the

user should have the following in mind: As a chip-erased device contains 0xFF in all

locations, programming of addresses that are meant to contain 0xFF, can be skipped.

This does not apply if the EEPROM is re-programmed without chip erasing the device.

In this case, data polling cannot be used for the value 0xFF, and the user will have to

wait at least t

WD_EEPROM

before programming the next byte. See Table 129 for

WD_EEPROM

value.

Figure 128. Serial Programming Waveforms

Table 129. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location

Symbol Minimum Wait Delay

WD_FLASH

4.5 ms

WD_EEPROM

9.0 ms

WD_ERASE

9.0 ms

MSB

LSB

SERIAL CLOCK INPUT

(SCK)

SERIAL DATA INPUT

(MOSI)

(MISO)

SAMPLE

SERIAL DATA OUTPUT

Table 130. Serial Programming Instruction Set

Instruction

Instruction Format

OperationByte 1 Byte 2 Byte 3 Byte4

Programming Enable 1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable Serial Programming after

RESET

goes low.

Chip Erase 1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip Erase EEPROM and Flash.

Read Program Memory 0010 H000 000a aaaa bbbb bbbb oooo oooo Read H (highorlow)datao from

Program memory at word address a:b.

Load Program Memory Page 0100 H000 000x xxxx xxbb bbbb iiii iiii Write H (high or low) data i to Program

Memory page at word address b.Data

low byte must be loaded before Data

high byte is applied within the same

address.

Write Program Memory Page 0100 1100 000aaaaa bbxx xxxx xxxx xxxx Write Program Memory Page at

address a:b.

Read EEPROM Memory 1010 0000 000x xxaa bbbb bbbb oooo oooo Read data o from EEPROM memory at

address a:b.

1 2 ... 276 277 278 279 280 281 282 283 284 285 286 ... 316 317

Commentaires sur ces manuels

Pas de commentaire

Rainbow-electronics Atmega169L Manuel d'utilisateur Page 281

Commentaires sur ces manuels

Produits connexes et manuels pour Capteurs Rainbow-electronics Atmega169L