TX4939XBG-400 Toshiba, TX4939XBG-400 Datasheet - Page 259

• 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

Video Port
12.3.5. Transmit Window Option
For transmit mode, TX4939 has special option to transfer a particular window of video data out to the video port.
In Figure 12-9 is an example of the Transmit Window Option. In the system memory, there is Window 1 data. These video
data are continuous in the memory. But the application want to transfer Window2 data output to the Video Port.
With the above setting, the VPC can transfer only the Video data in Window2 out to the Video port.
Rev. 3.1 November 1, 2005
In the Control 1 Descriptor, there are two field
In the Control 2 Descriptor, there are two field
DMAGA[31:0] should be programmed to point to the Start Address(Origin of Window2) as
shown in the Figure 12-9
Bcount[22:0] – this indicates the total number of bytes that the VPC want to transfer out. This
bytecount is the same as number of byte in Window2 in Figure 12-9
Note: Bcount[22:0] must be multple of validCount[11:0].
When Bcount[11:0] is not multple of validCount[11:0], undefined behavioral will occur in VPC.
validCount[11:0] specify the valid byte which equivalent to symbol A in the Figure 12-9
Offset[11:0] specifies the offset of the next address for the video data. Which is equivalent to the
value of symbol B plus symbol C in Figure 12-9
Origin of Window1
Skip (C) Bytes
Figure 12-9 Transmit Window 2 data to video port
Window1
C
Window2
Start Address (Origin of Window2)
A
12-7
First Scan
Second Scan
B
Skip (B) Bytes
Toshiba RISC Processor
Rev 1.01
TX4939
12
12