AT32UC3L0128 Datasheet, PDF (72/96 Pages) ATMEL Corporation – 32-bit Atmel AVR Microcontroller

AT32UC3L0128/256
TWIM and TWIS user interface registers. Please refer to the TWIM and TWIS sections for more
information.
Table 7-43. TWI-Bus Timing Requirements
Symbol
Parameter
Mode
Standard⁽¹⁾
t_r
TWCK and TWD rise time
Fast⁽¹⁾
Standard
t_f
TWCK and TWD fall time
Fast
t_HD-STA
Standard
(Repeated) START hold time
Fast
t_SU-STA
Standard
(Repeated) START set-up time
Fast
t_SU-STO STOP set-up time
Standard
Fast
t_HD-DAT
Data hold time
Standard
Fast
t_SU-DAT-TWI Data set-up time
Standard
Fast
t_SU-DAT
t_LOW-TWI TWCK LOW period
-
Standard
Fast
t_LOW
t_HIGH
TWCK HIGH period
-
Standard
Fast
f_TWCK
TWCK frequency
Standard
Fast
Minimum
Requirement
Device
-
20 + 0.1C_b
-
20 + 0.1C_b
4
t_clkpb
0.6
4.7
t_clkpb
0.6
4.0
4t_clkpb
0.6
0.3⁽²⁾
250
100
-
4.7
1.3
-
4.0
0.6
2t_clkpb
2t_clkpb
t_clkpb
4t_clkpb
t_clkpb
8t_clkpb
-
Maximum
Requirement
Device
Unit
1000
ns
300
300
ns
300
-
μs
-
μs
3.45⁽⁾
0.9⁽⁾
100
400
-
μs
15t_prescaled + t_clkpb μs
-
ns
-
-
-
μs
-
-
-
μs
-----------1------------
kHz
12tclkpb
Notes: 1. Standard mode: f_TWCK ≤ 100 kHz ; fast mode: f_TWCK > 100 kHz .
2. A device must internally provide a hold time of at least 300 ns for TWD with reference to the falling edge of TWCK.
Notations:
C_b = total capacitance of one bus line in pF
t_clkpb = period of TWI peripheral bus clock
t_prescaled = period of TWI internal prescaled clock (see chapters on TWIM and TWIS)
The maximum t_HD;DAT has only to be met if the device does not stretch the LOW period (t_LOW-TWI)
of TWCK.
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32145BS–01/2012