ST72T774J9B1 STMicroelectronics, ST72T774J9B1 Datasheet - Page 79

• Manufacturer Part Number: ST72T774J9B1
• Manufacturer: STMicroelectronics

Specifications of ST72T774J9B1

• Cpu Family: ST7
• Device Core Size: 8b
• Frequency (max): 24MHz
• Interface Type: I2C/USB
• Program Memory Type: EPROM
• Program Memory Size: 60KB
• Total Internal Ram Size: 1KB
• # I/os (max): 31
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 1-chx8-bit
• On-chip Dac: 1-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 42
• Package Type: SPDIP
• Lead Free Status / Rohs Status: Specific Sites Compliant

4.6 USB INTERFACE (USB)
4.6.1 Introduction
The USB Interface implements a low-speed
function interface between the USB and the ST7
microcontroller. It is a highly integrated circuit
which includes the transceiver, 3.3 voltage
regulator, SIE and DMA. No external components
are needed apart from the external pull-up on
USBDM for low speed recognition by the USB
host.
4.6.2 Main Features
4.6.3 Functional Description
The block diagram in
of the USB interface hardware.
For general information on the USB, refer to the
“Universal Serial Bus Specifications” document
available at http//:www.usb.org.
USBGND
USBVCC
USBDM
USB Specification Version 1.0 Compliant
Supports Low-Speed USB Protocol
Two or Three Endpoints (including default one)
depending on the device (see device feature list
and register map)
CRC generation/checking, NRZI encoding/
decoding and bit-stuffing
USB Suspend/Resume operations
DMA Data transfers
On-Chip 3.3V Regulator
On-Chip USB Transceiver
USBDP
Figure
Transceiver
Voltage
Regulator
3.3V
50, gives an overview
SIE
6 MHz
Serial Interface Engine
The SIE (Serial Interface Engine) interfaces with
the USB, via the transceiver.
The
transmission/reception,
required by the USB standard. It also performs
frame formatting, including CRC generation and
checking.
Endpoints
The
microcontroller is ready to transmit/receive, and
how many bytes need to be transmitted.
DMA
When a token for a valid Endpoint is recognized by
the USB interface, the related data transfer takes
place, using DMA. At the end of the transaction, an
interrupt is generated.
Interrupts
By
application software can know which USB event
has occurred.
Figure 50. USB block diagram
reading
REGISTERS
SIE
INTERRUPT
REGISTERS
Endpoint
ENDPOINT
DMA
processes
the
ST72774/ST727754/ST72734
registers
Interrupt
tokens,
and
indicate
Address,
data busses
and interrupts
handshaking
Status
handles
MEMORY
CPU
register,
if
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