TX4939XBG-400 Toshiba, TX4939XBG-400 Datasheet - Page 511

• Manufacturer Part Number: TX4939XBG-400
• Manufacturer: Toshiba

Specifications of TX4939XBG-400

• Cpu Core: TX49/H4 90nm
• Clock Mhz/max Mips: 400/520
• Inst./data Cache: 32KB (4 Way)/32KB (4 Way)
• Tlb: x
• 1cycle Mac: x
• Volts (v): 1.25/2.5/3.3
• Peripherals: DDR, NAND, ATA, ETHERNET, SECURITY, FPU, MMU, SPI, I2S, I2C, PCI, VIDEO, UART, TIMER, RTC
• Companion Chip: TC86C001FG
• Package: PGBA456

EMAC
18.3.7.2.2. BDStat field (buffer descriptor status)
In the case of a transmission queue, the Ethernet Controller does not use the BDStat field. In the case of a reception
queue, the BDStat field is used as the buffer ID. This value is copied from an empty buffer queue.
In the case of an empty buffer queue, the BDStat field is used to hand the buffer descriptor identification number to the
Ethernet Controller.
Rev. 3.1 November 1, 2005
Bits
7 : 0
Note:
Mnemonic
RXBDID
You can only apply buffer descriptor identification numbers freely if there are no more than 256 buffers in
a single buffer pool.
Field Name
Reception Buffer
Descriptor ID
Description
RXBDID
Value of the buffer descriptor identification number
Figure 18-9 BDStat Field
18-19
7
RxBDID
Toshiba RISC Processor
TX4939
0
18
18