STM32F21xxx
Electrical characteristics
Synchronous waveforms and timings
Figure 57 through Figure 60 represent synchronous waveforms and Table 74 through
Table 76 provide the corresponding timings. The results shown in these tables are obtained
with the following FSMC configuration:
● BurstAccessMode = FSMC_BurstAccessMode_Enable;
● MemoryType = FSMC_MemoryType_CRAM;
● WriteBurst = FSMC_WriteBurst_Enable;
● CLKDivision = 1; (0 is not supported, see the STM32F20xxx/21xxx reference manual)
● DataLatency = 1 for NOR Flash; DataLatency = 0 for PSRAM
In all timing tables, the THCLK is the HCLK clock period.
Figure 57. Synchronous multiplexed NOR/PSRAM read timings
tw(CLK)
tw(CLK)
BUSTURN = 0
FSMC_CLK
FSMC_NEx
td(CLKL-NADVL)
FSMC_NADV
FSMC_A[25:16]
Data latency = 0
td(CLKL-NExL)
td(CLKL-NADVH)
td(CLKL-AV)
t d(CLKL-NExH)
td(CLKL-AIV)
td(CLKH-NOEL) td(CLKL-NOEH)
FSMC_NOE
td(CLKL-ADV)
FSMC_AD[15:0]
td(CLKL-ADIV)
tsu(ADV-CLKH)
AD[15:0]
tsu(NWAITV-CLKH)
th(CLKH-ADV)
tsu(ADV-CLKH)
D1
D2
th(CLKH-ADV)
th(CLKH-NWAITV)
FSMC_NWAIT
(WAITCFG = 1b, WAITPOL + 0b)
FSMC_NWAIT
(WAITCFG = 0b, WAITPOL + 0b)
tsu(NWAITV-CLKH)
th(CLKH-NWAITV)
tsu(NWAITV-CLKH)
th(CLKH-NWAITV)
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