27
4173ES–USB–09/07
AT89C5132
VDD = 2.7 to 3.3 V, TA = -40 to +85°C

Notes: 1. At 100 kbit/s. At other bit-rates this value is inversely proportional to the bit-rate of 100 kbit/s.

2. Determined by the external bus-line capacitance and the external bus-line pull-up resistor, this

must be < 1 μs.

3. Spikes on the SDA and SCL lines with a duration of less than 3·TCLCL will be filtered out. Maxi-

mum capacitance on bus-lines SDA and

SCL= 400 pF.

4. TCLCL= TOSC= one oscillator clock period.

6.3.4.2 WaveformsFigure 6-16. Two Wire Wa veforms
Symbol Parameter
INPUT
Min
Max
OUTPUT
Min
Max
THD; STA Start condition hold time 14·TCLCL(4) 4.0 μs(1)
TLOW SCL low time 16·TCLCL(4) 4.7 μs(1)
THIGH SCL high time 14·TCLCL(4) 4.0 μs(1)
TRC SCL rise time 1 μs-
(2)
TFC SCL fall time 0.3 μs0.3 μs(3)
TSU; DAT1 Data set-up time 250 ns 20·TCLCL(4)- TRD
TSU; DAT2 SDA set-up time (before repeated START condition) 250 ns 1 μs(1)
TSU; DAT3 SDA set-up time (before STOP condition) 250 ns 8·TCLCL(4)
THD; DAT Data hold time 0 ns 8·TCLCL(4) - TFC
TSU; STA Repeated START set-up time 14·TCLCL(4) 4.7 μs(1)
TSU; STO STOP condition set-up time 14·TCLCL(4) 4.0 μs(1)
TBUF Bus free time 14·TCLCL(4) 4.7 μs(1)
TRD SDA rise time 1 μs -
(2)
TFD SDA fall time 0.3 μs0.3 μs(3)
Tsu;D AT1
Tsu;STA
Tsu; DAT2
Thd;STA Thigh
Tlow
SDA
(INPUT/OUTPUT) 0.3 VDD
0.7 VDD
Tbuf
Tsu;STO
0.7 VDD
0.3 VDD
Trd
Tfd
Trc Tfc
SCL
(INPUT/OUTPUT)
Thd;DAT
Tsu;DAT3
START or Repeated START condition START condition
STOP condition
Repeated START condition