3.5.2 Data Communication Timing


Parameter and Condition^{(1, 2)}	Symbol	Frame Type	Standard Speed⁽³⁾		High Speed		Units
Parameter and Condition^{(1, 2)}	Symbol	Frame Type	Min.	Max.	Min.	Max.	Units
Bit Frame Duration	t_BIT	Input and Output Bit Frame	40	100	t_LOW0 + t_PUP⁽⁴⁾ + t_RCV	25	µs
SI/O High Time for Start/Stop Condition	t_HTSS	Input Bit Frame	600	—	150	—	µs
SI/O Low Time, Logic ‘`0`’ Condition	t_LOW0	Input Bit Frame	24	64	6	16	µs
SI/O Low Time, Logic ‘`1`’ Condition	t_LOW1	Input Bit Frame	4	8	1	2	µs
Host SI/O Low Time During Read	t_RD	Output Bit Frame	4	8 - t_PUP⁽⁴⁾	1	2 - t_PUP⁽⁴⁾	µs
Host Read Strobe Time	t_MRS	Output Bit Frame	t_RD + t_PUP⁽⁴⁾	8	t_RD + t_PUP⁽⁴⁾	2	µs
Data Output Hold Time (Logic ‘`0`’)	t_HLD0	Output Bit Frame	8	24	2	6	µs
Client Recovery Time	t_RCV	Input and Output Bit Frame	8	—	2⁽⁵⁾	—	µs
Noise Filtering Capability on SI/O	t_NOISE	Input Bit Frame	0.5	—	—	—	µs

Note:

Parameters applicable over operating range in DC and AC Operating Range, unless otherwise noted.
AC measurement conditions for the table above:
- Loading capacitance on SI/O: 100 pF
- R_PUP (bus line pull-up resistor to V_PUP): 1 kΩ; V_PUP: 2.7V
Standard Speed is not available on the AT21CS11.
t_PUP is the time needed for the SI/O line to transition from V_IL to V_IH after being released. This value is specific to the application and depends on the loading capacitance on the SI/O line and the selected R_PUP. The use of additional client devices adds capacitance to the SI/O line and should be taken into consideration. Limits for these values are provided in AT21CS01 DC Characteristics and AT21CS11 DC Characteristics.
The system designer must select a combination of R_PUP, C_BUS and t_BIT such that the minimum t_RCV is satisfied. The relationship of t_RCV within the bit frame can be expressed by the following formula: t_BIT = t_LOW0 + t_PUP + t_RCV.