AT88SC25616C_09 Datasheet, PDF (5/20 Pages) ATMEL Corporation – CryptoMemory 256 Kbit

AT88SC25616C
Table 3. AC Characteristics
Applicable over recommended operating range from V_CC = +2.7 to 5.5V, T_AC = -40°C to +85°C, CL = 30pF
(unless otherwise noted)
Symbol
Parameter
Min
Max
Units
f_CLK
Async Clock Frequency (V_CC Range: +4.5 - 5.5V)
1
f_CLK
Async Clock Frequency (V_CC Range: +2.7 - 3.3V)
1
5
MHZ
4
MHZ
f_CLK
Synch Clock Frequency
0
1
MHZ
Clock Duty cycle
40
60
%
t_R
Rise Time - I/O, RST
1
μS
t_F
Fall Time - I/O, RST
1
μS
t_R
Rise Time - CLK
9% x period
μS
t_F
Fall Time - CLK
9% x period
μS
t_AA
Clock Low to Data Out Valid
35
nS
t_HD.STA Start Hold Time
200
nS
t_SU.STA
t_HD.DAT
Start Set-up Time
Data In Hold Time
200
nS
10
nS
t_SU.DAT Data In Set-up Time
100
nS
t_SU.STO
t_DH
Stop Set-up Time
Data Out Hold Time
200
nS
20
nS
t_WR
Write Cycle Time (at 25°C)
5
mS
t_WR
Write Cycle Time (-40° to +85°C)
7
mS
4. Device Operation for Synchronous Protocols
CLOCK and DATA TRANSITIONS: The SDA pin is normally pulled high with an external device. Data on the SDA pin
may change only during SCL low time periods (see Figure 5 on page 7). Data changes
during SCL high periods will indicate a start or stop condition as defined below.
START CONDITION:
A high-to-low transition of SDA with SCL high is a start condition which must precede any
other command (see Figure 6 on page 7).
STOP CONDITION:
A low-to-high transition of SDA with SCL high is a stop condition. After a read sequence, the
stop command will place the EEPROM in a standby power mode (see Figure 6 on page 7).
ACKNOWLEDGE:
All addresses and data words are serially transmitted to and from the EEPROM in 8-bit
words. The EEPROM sends a zero to acknowledge that it has received each word. This
happens during the ninth clock cycle.
MEMORY RESET:
After an interruption in protocol, power loss or system reset, any 2-wire part can be reset by
following these steps:
1. Clock up to 9 cycles.
2. Look for SDA high in each cycle while SCL is high.
3. Create a start condition.
5
5017KJS–SMEM–08/09