CD00237391 Datasheet, PDF (142/177 Pages) STMicroelectronics – ARM-based 32-bit MCU, 150DMIPs, up to 1 MB Flash/128+4KB RAM

Electrical characteristics
Figure 73. SD default mode
STM32F20xxx
CK
D, CMD
(output)
tOVD
tOHD
5.3.28
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Table 83. SD / MMC characteristics
Symbol
Parameter
Conditions
Min
f_PP
Clock frequency in data transfer
mode
C_L ≤ 30 pF
0
-
SDIO_CK/f_PCLK2 frequency ratio
-
-
t_W(CKL) Clock low time, f_PP = 16 MHz
C_L ≤ 30 pF
32
t_W(CKH) Clock high time, f_PP = 16 MHz
C_L ≤ 30 pF
31
t_r
Clock rise time
C_L ≤ 30 pF
t_f
Clock fall time
C_L ≤ 30 pF
CMD, D inputs (referenced to CK)
t_ISU
Input setup time
C_L ≤ 30 pF
2
t_IH
Input hold time
C_L ≤ 30 pF
0
CMD, D outputs (referenced to CK) in MMC and SD HS mode
t_OV
Output valid time
C_L ≤ 30 pF
t_OH
Output hold time
C_L ≤ 30 pF
0.3
CMD, D outputs (referenced to CK) in SD default mode⁽¹⁾
t_OVD Output valid default time
C_L ≤ 30 pF
t_OHD Output hold default time
C_L ≤ 30 pF
0.5
1. Refer to SDIO_CLKCR, the SDI clock control register to control the CK output.
Max Unit
48
MHz
8/3
-
ns
3.5
5
ns
6
ns
7
ns
RTC characteristics
Table 84. RTC characteristics
Symbol
Parameter
Conditions
Min
Max
-
f_PCLK1/RTCCLK frequency ratio
Any read/write operation
from/to an RTC register
4
-
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Doc ID 15818 Rev 9