AN2131QC 参数 Datasheet PDF下载

型号：	AN2131QC
PDF下载：	下载PDF文件查看货源
内容描述：	在EZ - USBTM集成电路 [The EZ-USBTM Integrated Circuit]
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文件页数/大小：	334 页 / 1468 K
品牌：	CYPRESS [ CYPRESS ]

Table 8-1. Isochronous Endpoint FIFO Starting Address Registers

OUT8ADDR Endpoint 8 OUT Start Address

OUT9ADDR Endpoint 9 OUT Start Address

OUT10ADDR Endpoint 10 OUT Start Address

OUT11ADDR Endpoint 11 OUT Start Address

OUT12ADDR Endpoint 12 OUT Start Address

OUT13ADDR Endpoint 13 OUT Start Address

OUT14ADDR Endpoint 14 OUT Start Address

OUT15ADDR Endpoint 15 OUT Start Address

A8 A7 A6 A5 A4

IN8ADDR

IN9ADDR

IN10ADDR

IN11ADDR

IN12ADDR

IN13ADDR

IN14ADDR

IN15ADDR

Endpoint 8 IN Start Address

Endpoint 9 IN Start Address

Endpoint 10 IN Start Address

Endpoint 11 IN Start Address

Endpoint 12 IN Start Address

Endpoint 13 IN Start Address

Endpoint 14 IN Start Address

Endpoint 15 IN Start Address

The size of an isochronous endpoint FIFO is determined by subtracting consecutive

addresses in Table 8-1, and multiplying by four. Values written to these registers should

have the two LSBs set to zero. The last endpoint, EP15IN, has a size of 1,024 minus

IN15ADDR times four. Because the 10-bit effective address has the four LSBs set to zero

(Figure 8-4), the FIFO sizes are allocated in increments of 16 bytes. For example, if

OUT8ADDR=0x00 and OUT9ADDR=0x04, EP8OUT has a FIFO size of the difference

multiplied by four or 16 bytes.

An 8051 assembler or C compiler may be used to translate FIFO sizes into starting

addresses. The assembler example in Figure 8-5 shows a block of equates for the 16 iso-

chronous FIFO sizes, followed by assembler equations to compute the corresponding

FIFO relative address values. To initialize all sixteen FIFO sizes, the 8051 merely copies

the table starting at 8OUTAD to the sixteen EZ-USB registers starting at OUT8ADDR.

Page 8-6

Chapter 8. EZ-USB CPU

EZ-USB TRM v1.9