EP9312-IB Cirrus Logic Inc, EP9312-IB Datasheet - Page 324

• Manufacturer Part Number: EP9312-IB
• Description: IC ARM920T MCU 200MHZ 352-PBGA
• Manufacturer: Cirrus Logic Inc
• Series: EP9r

Specifications of EP9312-IB

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 200MHz
• Connectivity: EBI/EMI, EIDE, Ethernet, I²C, IrDA, Keypad/Touchscreen, SPI, UART/USART, USB
• Peripherals: AC'97, DMA, I&sup2:S, LCD, LED, MaverickKey, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 3.6 V
• Data Converters: A/D 8x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 352-BGA
• Processor Series: EP93xx
• Core: ARM920T
• Data Bus Width: 32 bit
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: No
• Other names: 598-1259

9
9-22
1/10/100 Mbps Ethernet LAN Controller
EP93xx User’s Guide
9.2.3.3 Receive Errors
Refer to the circled numbers in
Receive error conditions are broken into two categories: hard errors and soft errors. A hard
error is generally considered a reliability problem. This includes AHB bus access problems. A
soft error indicates that the frame was not successfully received. The error may be expected
or rare. A soft error needs a graceful recovery by the host driver. Soft errors include: CRC
errors, receiver over-run, frames too long, or frames too short. Hard errors are parity errors
(when enabled), system errors, and master or target aborts, these errors will stop receive
DMA activity, and require host intervention for recovery. Recovery may be achieved by
performing a RxChRes (Bus Master Control) and reinitializing.
Note:
Note: Steps 1, 11, and 13 are transparent to the MAC. Steps 2 through 10 and 12 directly involve
1. Driver initializes some number of receive descriptors.
2. Driver writes RXDEnq register with the additional number of receive descriptors.
3. On-chip Descriptor Processor fetches descriptors into internal FIFO decrements
4. The address of the next receive data buffer is loaded into the Receive Buffer Current
5. A frame is received from the LAN medium.
6. The MAC Engine passes the frame data to the Receive Data FIFO.
7. The Receive Descriptor Processor stores the frame data into system memory.
8. End of frame status is written to the Receive Status Queue the RXStsEnq value reduced
9. Driver interrupted if interrupt conditions met.
10.Received frame passed to the protocol stack.
11.Driver clears the Receive Frame Processed bit in Status Queue.
12.Driver writes number of entries processed in the status queue, freeing them for future
13.After the driver gets the used receive buffers back from the stack, the driver may repeat
RXDEnq appropriately.
Address.
by one.
use by the MAC.
step 2.
the MAC.
Steps 5, 6, and 7 can overlap.
Copyright 2007 Cirrus Logic
Figure
9-9. The detailed receive flow is:
DS785UM1