UPD70F3786GJ-GAE-AX Renesas Electronics America, UPD70F3786GJ-GAE-AX Datasheet - Page 1491

• Manufacturer Part Number: UPD70F3786GJ-GAE-AX
• Description: MCU 32BIT V850ES/JX3-E 144-LQFP
• Manufacturer: Renesas Electronics America
• Series: V850ES/Jx3-Er

Specifications of UPD70F3786GJ-GAE-AX

• Core Processor: RISC
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: CAN, CSI, EBI/EMI, Ethernet, I²C, UART/USART, USB
• Peripherals: DMA, LVD, PWM, WDT
• Number Of I /o: 100
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 124K x 8
• Voltage - Supply (vcc/vdd): 2.85 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

(a) When a frame is received, data is stored in the receive FIFO.
(b) A back pressure request is issued when the amount of data in the receive FIFO exceeds the value indicated by FLOWTHR.
(c) Back pressure is performed if the next frame is received in this status.
(d) When the amount of data in the receive FIFO falls below the value indicated by FLOWTHR, the back pressure request is canceled.
(2) Back pressure
This function is available only during half-duplex operation.
If the amount of data in the receive FIFO exceeds the set value of FLOWTHRESH.FLOWTHR when
MFFCONT.FLOWCNT is set to 1 and FULLD is 0, the Ethernet controller issues a back pressure request (refer
to Figure 23-11 (b)).
If the next frame is received in this status, a collision is intentionally generated by transmitting a dummy packet,
prompting the other terminal to retransmit the frame (refer to Figure 23-11 (c)).
A collision that occurrs in the back pressure status is not included in the number of collisions. The back
pressure status is canceled when the amount of data in the receive FIFO falls below the value of FLOWTHR
(refer to Figure 23-11 (d)).
DMAC
DMAC
DMAC
DMAC
CHAPTER 23 ETHERNET CONTROLLER
Receive FIFO
Receive FIFO
Figure 23-11. Back Pressure Control
Receive FIFO
Receive FIFO
User’s Manual U19601EJ2V0UD
Back pressure request
Back pressure request
FLOWTHR
FLOWTHR
FLOWTHR
FLOWTHR
MAC
MAC
MAC
MAC
The other terminal detects a collision by
back pressure and retransmits the frame
by a random back-off algorithm.
Frame reception
Frame reception
Frame reception
Pause control
frame reception
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