ST72651AR6 STMicroelectronics, ST72651AR6 Datasheet - Page 61

• Manufacturer Part Number: ST72651AR6
• Description: LOW-POWER, FULL-SPEED USB 8-BIT MCU WITH 32K FLASH, 5K RAM, FLASH CARD I/F, TIMER, PWM, ADC, I2C, SPI
• Manufacturer: STMicroelectronics

Specifications of ST72651AR6

• Dual Supply Management: analog voltage detector on the USB power line to enable smart power switching from USB power to battery (on E suffix devices).
• Programmable Internal Voltage Regulator For Memory Cards (2.8v To 3.5v) Supplying: Flash Card I/O lines (voltage shifting)
• 5 Usb Endpoints: 1 control endpoint
• Dtc (data Transfer Coprocessor): Universal Serial/Parallel communications interface, with software plug-ins for current and future protocol standards

11.3 USB INTERFACE (USB)
11.3.1 Introduction
The USB Interface implements a full-speed func-
tion interface between the USB and the ST7 mi-
crocontroller. It is a highly integrated circuit which
includes the transceiver, 3.3 voltage regulator, SIE
and USB Data Buffer interface. No external com-
ponents are needed apart from the external pull-
up on USBDP for full speed recognition by the
USB host.
11.3.2 Main Features
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11.3.3 Functional Description
The block diagram in
of the USB interface hardware.
Figure 36. USB Block Diagram
USBGND
USBVCC
USBDM
USB Specification Version 2.0 Compliant
Supports Full-Speed USB Protocol
Five Endpoints (including default endpoint)
CRC generation/checking, NRZI encoding/
decoding and bit-stuffing
USB Suspend/Resume operations
Special Data transfer mode with USB Data
Buffer Memory (2 x 512 bytes for upload or
download) to DTC
On-Chip 3.3V Regulator
On-Chip USB Transceiver
USBDP
Figure
Transceiver
Voltage
Regulator
3.3V
36, gives an overview
Doc ID 7215 Rev 4
SIE
48 MHz
For general information on the USB, refer to the
“Universal Serial Bus Specifications” document
available at http//:www.usb.org.
Serial Interface Engine
The SIE (Serial Interface Engine) interfaces with
the USB, via the transceiver.
The SIE processes tokens, handles data transmis-
sion/reception, and handshaking as required by
the USB standard. It also performs frame format-
ting, including CRC generation and checking.
Endpoints
The Endpoint registers indicate if the microcon-
troller is ready to transmit/receive, and how many
bytes need to be transmitted.
Data Transfer to/from USB Data Buffer Memory
When a token for a valid Endpoint is recognized by
the USB interface, the related data transfer takes
place to/from the USB data buffer. In normal con-
figuration (MOD[1:0] bits=00 in the CTLR register),
at the end of the transaction, an interrupt is gener-
ated.
Interrupts
By reading the Interrupt Status register, applica-
tion software can know which USB event has oc-
curred.
INTERFACE
REGISTERS
REGISTERS
ENDPOINT
BUFFER
USB
Address,
data busses
and interrupts
ST72651AR6
BUFFER
DATA
USB
CPU
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