UPSD3433EB40U6 STMicroelectronics, UPSD3433EB40U6 Datasheet - Page 146

• Manufacturer Part Number: UPSD3433EB40U6
• Description: MCU 8BIT 8032 128KB FLASH 80TQFP
• Manufacturer: STMicroelectronics
• Series: µPSDr

Specifications of UPSD3433EB40U6

• Core Processor: 8032
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, IrDA, SPI, UART/USART, USB
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 46
• Program Memory Size: 160KB (160K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP, 80-VQFP
• For Use With: 497-5518 - EVAL BOARD RFID READER497-5046 - KIT TOOL FOR ST7/UPSD/STR7 MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 497-5660

USB interface
25.1.4
146/293
The data packet contains a DATA1 or DATA0 PID. In a USB system, the host or device that is
sending data is responsible for toggling the data PID between DATA0 and DATA1. The
receiving device keeps track of the Toggle Bit and compares it with the data PID that is
received. This provides a means for the receiving host or device to detect a corrupted
handshake packet. The Payload Data is the data that the host is sending to the device and
the CRC16 is used for error checking.
For an OUT transaction, the host sends the token and data packets. The receiving device
sends a handshake packet to notify the host whether it was able to accept the packet or not.
There are three handshake PIDs as follows:
●
●
●
Figure 50. USB Packets in a USB Transfer Example
Data transfers with the host
The host issues OUT tokens followed by Data Tokens to send data to a device. The device
responds with an appropriate handshake packet (ACK/NAK), indicating whether it was able
to receive the data. If the device does not receive the data packet OK (because there is
some error), it does not respond with a handshake packet. In the case of a NAK or no
response, the host retries sending the data at a later time.
USB devices are not able to send data to a host whenever they have it ready. When a device
has data ready, it loads data into its endpoint buffer, making it ready for a transfer. The data
will remain in the buffer until the host issues an IN token to that device’s endpoint, at which
time the data will be sent. If the host receives the data OK, it follows with an ACK handshake
(a host never NAKs). If the host did not receive the data OK, there is no handshake packet.
In this case, the device should reload its endpoint buffer as appropriate and the host will
retry again later to retrieve the data.
ACK: this PID indicates that the device received the data successfully.
NAK: this handshake indicates that the device was not able to receive the data (it is
busy). A NAK does not mean there was an error, since errors are indicated by a “no
handshake” packet. When the host receives a NAK PID or does not receive a
handshake packet at all, the host retries sending the data at a later time.
STALL: this handshake indicates that something is wrong. For example, the host has
sent a device request that is not understood, the host is trying to access a resource that
is not available, or something is wrong with the device.
OUT
OUT
ADDR
ADDR
Token Packet
Token Packet
1
4
ENDP
ENDP
CRC5
CRC5
Data1
Data0
Data Packet
Data Packet
Payload
Payload
Data
Data
2
5
CRC16
CRC16
Handshake Packet
Handshake Packet
ACK
ACK
3
6
AI10489
uPSD34xx