UPSD3422E-40U6 STMicroelectronics, UPSD3422E-40U6 Datasheet - Page 138

• Manufacturer Part Number: UPSD3422E-40U6
• Description: MCU 8BIT 8032 64KB FLASH 80TQFP
• Manufacturer: STMicroelectronics
• Series: µPSDr

Specifications of UPSD3422E-40U6

• 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: 80KB (80K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K 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: 497-5577 - BOARD EVAL USB POWER SWITCH497-5518 - EVAL BOARD RFID READER
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 497-4903

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2
C interface
Interrupt service routine (ISR)
A typical I
combinations of Master/Slave and Transmitter/Receiver. In the example routines above, the
firmware sets global variables, I2C_master and I2C_xmitter, before enabling interrupts.
These flags tell the ISR which one of the four cases to process. Following is pseudo-code for
high-level steps in the I
Begin I2C ISR <I2C interrupt just occurred>:
Clear I2C interrupt flag:
Read status of SIOE, put in to variable, status
Read global variables that determine the mode
If mode is Master-Transmitter
ACK recvd from Slave? (status.ACK_RESP=0?)
Was that the last byte of data to transmit?
–
–
–
–
–
–
–
–
–
–
–
–
<Stop occurs after ISR exit>
–
–
S1STA.INTR = 0
status = S1STA
mode <= (I2C_master, I2C_slave)
Bus Arbitration lost? (status.BLOST=1?)
If Yes, Arbitration was lost:
S1DAT = dummy, write to release bus
Exit ISR, SIOE will switch to Slave Recv mode
If No, Arbitration was not lost, continue:
If No, an ACK was not received:
S1CON.STO = 1, set Stop bus condition
<Stop occurs after ISR exit>
S1DAT = dummy, write to release bus
Exit ISR
If Yes, ACK was received, then continue:
S1DAT = xmit_buf[buffer_index], transmit byte
If No, it was not the last byte, then:
Exit ISR, transmit next byte on next interrupt
If Yes, it was the last byte, then:
S1CON.STO = 1, set Stop bus condition
S1DAT = dummy, write to release bus
Exit ISR
2
C interrupt service routine would handle a interrupt for any of the four
2
C ISR:
UPSD3422, UPSD3433, UPSD3434, UPSD3454