Datasheet

DocID17050 Rev 9 35/175
STM32F21xxx Functional overview
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3.31.1 Cryptographic acceleration
The STM32F215xx and STM32F217xx devices embed a cryptographic accelerator. This
cryptographic accelerator provides a set of hardware acceleration for the advanced
cryptographic algorithms usually needed to provide confidentiality, authentication, data
integrity and non repudiation when exchanging messages with a peer.
• These algorithms consists of:
Encryption/Decryption
– DES/TDES (data encryption standard/triple data encryption standard): ECB
(electronic codebook) and CBC (cipher block chaining) chaining algorithms, 64-,
128- or 192-bit key
– AES (advanced encryption standard): ECB, CBC and CTR (counter mode)
chaining algorithms, 128, 192 or 256-bit key
Universal hash
– SHA-1 (secure hash algorithm)
–MD5
• It also provides a true random number generator that deliver 32-bit random numbers
produced by an integrated analog circuit.
3.32 True random number generator (RNG)
All STM32F2xxx products embed a true RNG that delivers 32-bit random numbers
produced by an integrated analog circuit.
3.33 GPIOs (general-purpose inputs/outputs)
Each of the GPIO pins can be configured by software as output (push-pull or open-drain,
with or without pull-up or pull-down), as input (floating, with or without pull-up or pull-down)
or as peripheral alternate function. Most of the GPIO pins are shared with digital or analog
alternate functions. All GPIOs are high-current-capable and have speed selection to better
manage internal noise, power consumption and electromagnetic emission.
The I/O alternate function configuration can be locked if needed by following a specific
sequence in order to avoid spurious writing to the I/Os registers.
To provide fast I/O handling, the GPIOs are on the fast AHB1 bus with a clock up to
120 MHz that leads to a maximum I/O toggling speed of 60 MHz.
3.34 ADCs (analog-to-digital converters)
Three 12-bit analog-to-digital converters are embedded and each ADC shares up to 16
external channels, performing conversions in the single-shot or scan mode. In scan mode,
automatic conversion is performed on a selected group of analog inputs.
Additional logic functions embedded in the ADC interface allow:
• Simultaneous sample and hold
• Interleaved sample and hold