收藏本站
Universal serial bus full-speed device interface (USB)
Table 152. Double-buffering buffer flag definition
RM0008
Buffer flag
DTOG
SW_BUF
‘Transmission’ endpoint
DTOG_TX (USB_EPnRbit 6)
USB_EPnR bit 14
‘Reception’ endpoint
DTOG_RX (USB_EPnRbit 14)
USB_EPnR bit 6
The memory buffer which is currently being used by the USB peripheral is defined by DTOG
buffer flag, while the buffer currently in use by application software is identified by SW_BUF
buffer flag. The relationship between the buffer flag value and the used packet buffer is the
same in both cases, and it is listed in the following table.
Table 153. Bulk double-buffering memory buffers usage
Endpoint
Type
DTOG SW_BUF
Packet buffer used by USB
Peripheral
Packet buffer used by
Application Software
0
1
ADDRn_TX_0 / COUNTn_TX_0 ADDRn_TX_1 / COUNTn_TX_1
Buffer description table locations. Buffer description table locations.
1
0
ADDRn_TX_1 / COUNTn_TX_1
Buffer description table locations
ADDRn_TX_0 / COUNTn_TX_0
Buffer description table locations.
IN
0
1
0
1
None (1)
None (1)
ADDRn_TX_0 / COUNTn_TX_0
Buffer description table locations.
ADDRn_TX_0 / COUNTn_TX_0
Buffer description table locations.
OUT
0
1
1
0
ADDRn_RX_0 / COUNTn_RX_0 ADDRn_RX_1 / COUNTn_RX_1
Buffer description table locations. Buffer description table locations.
ADDRn_RX_1 / COUNTn_RX_1 ADDRn_RX_0 / COUNTn_RX_0
Buffer description table locations. Buffer description table locations.
0
1
0
1
None (1)
None (1)
ADDRn_RX_0 / COUNTn_RX_0
Buffer description table locations.
ADDRn_RX_1 / COUNTn_RX_1
Buffer description table locations.
1. Endpoint in NAK Status.
Double-buffering feature for a bulk endpoint is activated by:
●
●
Writing EP_TYPE bit field at ‘00’ in its USB_EPnR register, to define the endpoint as a
bulk, and
Setting EP_KIND bit at ‘1’ (DBL_BUF), in the same register.
The application software is responsible for DTOG and SW_BUF bits initialization according
to the first buffer to be used; this has to be done considering the special toggle-only property
that these two bits have. The end of the first transaction occurring after having set
DBL_BUF, triggers the special flow control of double-buffered bulk endpoints, which is used
for all other transactions addressed to this endpoint until DBL_BUF remain set. At the end of
each transaction the CTR_RX or CTR_TX bit of the addressed endpoint USB_EPnR
register is set, depending on the enabled direction. At the same time, the affected DTOG bit
in the USB_EPnR register is hardware toggled making the USB peripheral buffer swapping
completely software independent. Unlike common transactions, and the first one after
522/995
Doc ID 13902 Rev 9
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
MCBTMPM330 BOARD EVAL TOSHIBA TMPM330 SER
MCIMX25WPDKJ KIT DEVELOPMENT WINCE IMX25
MCIMX53-START-R KIT DEVELOPMENT I.MX53
MCM69C432TQ20 IC CAM 1MB 50MHZ 100LQFP
MCP1401T-E/OT IC MOSFET DRVR INV 500MA SOT23-5
MCP1403T-E/MF IC MOSFET DRIVER 4.5A DUAL 8DFN
MCP1406-E/SN IC MOSFET DVR 6A 8SOIC
MCP14628T-E/MF IC MOSFET DVR 2A SYNC BUCK 8-DFN
相关代理商/技术参数
MCBSTM32EXLU 功能描述:开发板和工具包 - ARM EVAL BOARD + ULINK2 FOR STM32F103ZG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32EXLU-ED 制造商:ARM Ltd 功能描述:KEIL STM STM32EXL EVAL BOARD
MCBSTM32EXLUME 功能描述:开发板和工具包 - ARM EVAL BOARD + ULINKME FOR STM32F103ZG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200U 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG + ULINK2 RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200UME 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F207IG ULINK-ME RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
MCBSTM32F200UME-ED 制造商:ARM Ltd 功能描述:KEIL STM32F207IG EVAL BOARD
MCBSTM32F400 功能描述:开发板和工具包 - ARM EVAL BOARD FOR STM STM32F407IG RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V