K20P144M120SF3 Datasheet, PDF (38/80 Pages) Freescale Semiconductor, Inc – K20 Sub-Family Data Sheet

Peripheral operating requirements and behaviors
In case the reciprocal of SCALER is an integer, the duty cycle of NFC clock is 50%,
means T_H = T_L. In case the reciprocal of SCALER is not an integer:
T _L = (1 + SCALER / 2) x
T _NFC
2
T _H = (1 – SCALER / 2) x
T _NFC
2
For example, if SCALER is 0.2, then T_H = T_L = T_NFC/2.
T_NFC
T_H T_L
However, if SCALER is 0.667, then T_L = 2/3 x T_NFC and T_H = 1/3 x T_NFC.
T_NFC
T_H T_L
Num
t_CLS
t_CLH
t_CS
t_CH
t_WP
t_ALS
t_ALH
t_DS
t_DH
t_WC
t_WH
t_RR
t_RP
38
NOTE
The reciprocal of SCALER must be a multiple of 0.5. For
example, 1, 1.5, 2, 2.5, etc.
Table 24. NFC specifications
Description
Min.
Max.
Unit
NFC_CLE setup time
NFC_CLE hold time
NFC_CEn setup time
NFC_CEn hold time
NFC_WP pulse width
NFC_ALE setup time
NFC_ALE hold time
Data setup time
Data hold time
Write cycle time
NFC_WE hold time
Ready to NFC_RE low
NFC_RE pulse width
2T_H + T_L – 1
—
ns
T_H + T_L – 1
—
ns
2T_H + T_L – 1
—
ns
T_H + T_L
—
ns
T_L – 1
—
ns
2T_H + T_L
—
ns
T_H + T_L
—
ns
T_L – 1
—
ns
T_H – 1
—
ns
T_H + T_L – 1
—
ns
T_H – 1
—
ns
4T_H + 3T_L + 90
—
ns
T_L + 1
—
ns
Table continues on the next page...
K20 Sub-Family Data Sheet Data Sheet, Rev. 3, 2/2012.
Preliminary
Freescale Semiconductor, Inc.