ATA5771-DK1 Atmel, ATA5771-DK1 Datasheet - Page 24

• Manufacturer Part Number: ATA5771-DK1
• Description: BOARD XMITTER FOR ATA5771 868MHZ
• Manufacturer: Atmel
• Type: Transmitterr

Specifications of ATA5771-DK1

• Frequency: 868MHz
• Maximum Frequency: 868 MHz
• Supply Voltage (max): 4 V
• Supply Voltage (min): 2 V
• Supply Current: 8.5 mA
• Product: RF Development Tools
• For Use With/related Products: ATA5771
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.8.3
4.8.3.1
4.8.3.2
4.8.3.3
4.8.3.4
24
Atmel ATA5771/73/74
EEPROM Data Memory
EEPROM Read/Write Access
Atomic Byte Programming
Split Byte Programming
Erase
The Atmel
arate data space, in which single bytes can be read and written. The EEPROM has an
endurance of at least 100,000 write/erase cycles. The access between the EEPROM and the
CPU is described in the following, specifying the EEPROM Address Registers, the EEPROM
Data Register, and the EEPROM Control Register. For a detailed description of Serial data
downloading to the EEPROM, see
The EEPROM Access Registers are accessible in the I/O space.
The write access times for the EEPROM are given in
tion, however, lets the user software detect when the next byte can be written. If the user code
contains instructions that write the EEPROM, some precautions must be taken. In heavily
filtered power supplies, V
device for some period of time to run at a voltage lower than specified as minimum for the
clock frequency used. See
details on how to avoid problems in these situations.
In order to prevent unintentional EEPROM writes, a specific write procedure must be followed.
See
Programming” on page 24
When the EEPROM is read, the CPU is halted for four clock cycles before the next instruction
is executed. When the EEPROM is written, the CPU is halted for two clock cycles before the
next instruction is executed.
Using Atomic Byte Programming is the simplest mode. When writing a byte to the EEPROM,
the user must write the address into the EEARL Register and data into EEDR Register. If the
EEPMn bits are zero, writing EEPE (within four cycles after EEMPE is written) will trigger the
erase/write operation. Both the erase and write cycle are done in one operation and the total
programming time is given in Table 1. The EEPE bit remains set until the erase and write
operations are completed. While the device is busy with programming, it is not possible to do
any other EEPROM operations.
It is possible to split the erase and write cycle in two different operations. This may be useful if
the system requires short access time for some limited period of time (typically if the power
supply voltage falls). In order to take advantage of this method, it is required that the locations
to be written have been erased before the write operation. But since the erase and write oper-
ations are split, it is possible to do the erase operations when the system allows doing
time-critical operations (typically after Power-up).
To erase a byte, the address must be written to EEAR. If the EEPMn bits are 0b01, writing the
EEPE (within four cycles after EEMPE is written) will trigger the erase operation only (pro-
gramming time is given in Table 1). The EEPE bit remains set until the erase operation
completes. While the device is busy programming, it is not possible to do any other EEPROM
operations.
Section 4.8.3.2 “Atomic Byte Programming” on page 24
®
ATtiny44V contains 256 bytes of data EEPROM memory. It is organized as a sep-
CC
for details on this.
Section 4.8.3.6 “Preventing EEPROM Corruption” on page 27
is likely to rise or fall slowly on Power-up/down. This causes the
Section 4.23.6 “Serial Downloading” on page
Table 4-2 on page
and
Section 4.8.3.3 “Split Byte
30. A self-timing func-
9137E–RKE–12/10
169.
for