AT89C5130A-M Atmel Corporation, AT89C5130A-M Datasheet - Page 43

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AT89C5130A-M

Manufacturer Part Number
AT89C5130A-M
Description
Manufacturer
Atmel Corporation
Datasheets

Specifications of AT89C5130A-M

Flash (kbytes)
16 Kbytes
Max. Operating Frequency
48 MHz
Cpu
8051-12C
Max I/o Pins
34
Usb Transceiver
1
Usb Speed
Full Speed
Usb Interface
Device
Spi
1
Twi (i2c)
1
Uart
1
Sram (kbytes)
1.25
Eeprom (bytes)
1024
Self Program Memory
API
Operating Voltage (vcc)
2.7 to 5.5
Timers
4
Isp
UART/USB
Watchdog
Yes
10. EEPROM Data Memory
10.1
10.2
10.3
10.4
4337K–USB–04/08
Description
Write Data in the Column Latches
Programming
Read Data
The 1-Kbyte on-chip EEPROM memory block is located at addresses 0000h to 03FFh of the
ERAM memory space and is selected by setting control bits in the EECON register.
A read in the EEPROM memory is done with a MOVX instruction.
A physical write in the EEPROM memory is done in two steps: write data in the column latches
and transfer of all data latches into an EEPROM memory row (programming).
The number of data written on the page may vary from 1 to 128 bytes (the page size). When pro-
gramming, only the data written in the column latch is programmed and a ninth bit is used to
obtain this feature. This provides the capability to program the whole memory by bytes, by page
or by a number of bytes in a page. Indeed, each ninth bit is set when the writing the correspond-
ing byte in a row and all these ninth bits are reset after the writing of the complete EEPROM row.
Data is written by byte to the column latches as for an external RAM memory. Out of the 11
address bits of the data pointer, the 4 MSBs are used for page selection (row) and 7 are used for
byte selection. Between two EEPROM programming sessions, all the addresses in the column
latches must stay on the same page, meaning that the 4 MSB must not be changed.
The following procedure is used to write to the column latches:
The EEPROM programming consists on the following actions:
The following procedure is used to read the data stored in the EEPROM memory:
• Set bit EEE of EECON register
• Load DPTR with the address to write
• Store A register with the data to be written
• Execute a MOVX @DPTR, A
• If needed, loop the three last instructions until the end of a 128 bytes page
• Writing one or more bytes of one page in the column latches. Normally, all bytes must belong
• Launching programming by writing the control sequence (52h followed by A2h) to the
• EEBUSY flag in EECON is then set by hardware to indicate that programming is in progress
• The end of programming is indicated by a hardware clear of the EEBUSY flag.
• Set bit EEE of EECON register
• Stretch the MOVX to accommodate the slow access time of the column latch (Set bit M0 of
• Load DPTR with the address to read
• Execute a MOVX A, @DPTR
to the same page; if not, the first page address will be latched and the others discarded.
EECON register.
and that the EEPROM segment is not available for reading.
AUXR register)
AT89C5130A/31A-M
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