收藏本站
...the world's most energy friendly microcontrollers
Bit
Name
Description
At the start of a DMA cycle, or 2 DMA transfer, the controller fetches the channel_cfg from system
memory. After it performs 2 , or N, transfers it stores the updated channel_cfg in system memory.
When the controller operates in peripheral scatter-gather mode, you must only use this
value in the alternate data structure.
R
R
The controller does not support a dst_size value that is different to the src_size value. If it detects a
mismatch in these values, it uses the src_size value for source and destination and when it next updates
the n_minus_1 field, it also sets the dst_size field to the same as the src_size field.
After the controller completes the N transfers it sets the cycle_ctrl field to b000, to indicate that the
channel_cfg data is invalid. This prevents it from repeating the same DMA transfer.
8.4.3.4 Address calculation
To calculate the source address of a DMA transfer, the controller performs a left shift operation on the
n_minus_1 value by a shift amount that src_inc specifies, and then subtracts the resulting value from the
source data end pointer. Similarly, to calculate the destination address of a DMA transfer, it performs a
left shift operation on the n_minus_1 value by a shift amount that dst_inc specifies, and then subtracts
the resulting value from the destination end pointer.
Depending on the value of src_inc and dst_inc, the source address and destination address can be
calculated using the equations:
src_inc = b00 and dst_inc = b00
src_inc = b01 and dst_inc = b01
src_inc = b10 and dst_inc = b10
src_inc = b11 and dst_inc = b11
?
?
?
?
?
?
?
?
source address = src_data_end_ptr - n_minus_1
destination address = dst_data_end_ptr - n_minus_1.
source address = src_data_end_ptr - (n_minus_1 << 1)
destination address = dst_data_end_ptr - (n_minus_1 << 1).
source address = src_data_end_ptr - (n_minus_1 << 2)
destination address = dst_data_end_ptr - (n_minus_1 << 2).
source address = src_data_end_ptr
destination address = dst_data_end_ptr.
Table 8.10 (p. 56) lists the destination addresses for a DMA cycle of six words.
Table 8.10. DMA cycle of six words using a word increment
Initial values of channel_cfg, prior to the DMA cycle
src_size = b10, dst_inc = b10, n_minus_1 = b101, cycle_ctrl = 1
End Pointer
0x2AC
0x2AC
Count
5
4
Difference
0x14
0x10
1
Address
0x298
0x29C
DMA transfers
0x2AC
0x2AC
0x2AC
0x2AC
3
2
1
0
0xC
0x8
0x4
0x0
0x2A0
0x2A4
0x2A8
0x2AC
This value is the result of count being shifted left by the value of dst_inc.
Final values of channel_cfg, after the DMA cycle
src_size = b10, dst_inc = b10, n_minus_1 = 0, cycle_ctrl = 0
1
Table 8.11 (p. 57) lists the destination addresses for a DMA transfer of 12 bytes using a halfword
increment.
2011-04-12 - d0001_Rev1.10
56
www.energymicro.com
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
EFM32GG-STK3700 KIT STARTER GIANT GECKO
EFM32LG-DK3650 KIT DEV EFM32 LEOPARD GECKO
EK-K7-KC705-CES-G-J KINTEX-7 FPGA KC705 EVAL KIT
EK-S6-SP601-G KIT EVAL SPARTAN 6 SP601
EK-S6-SP605-G KIT EVAL SPARTAN 6 SP605
EK-V6-ML631-G-J VIRTEX-6 HXT FPGA ML631 EVAL KIT
EK-V7-VC707-CES-G VIRTEX-7 VC707 EVAL KIT
EK-Z7-ZC702-CES-G ZYNQ-7000 EPP ZC702 EVAL KIT
相关代理商/技术参数
EFM32GG230F1024 功能描述:ARM微控制器 - MCU 1024KB FL 128KB RAM RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 处理器系列:STM32F373xx 数据总线宽度:32 bit 最大时钟频率:72 MHz 程序存储器大小:256 KB 数据 RAM 大小:32 KB 片上 ADC:Yes 工作电源电压:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LQFP-48 安装风格:SMD/SMT
EFM32GG230F1024G-E-QFN64R 功能描述:IC MCU 32BIT 1MB FLASH 64QFN 制造商:silicon labs 系列:Giant Gecko 包装:剪切带（CT） 零件状态:在售 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:48MHz 连接性:I2C，IrDA，智能卡，SPI，UART/USART 外设:欠压检测/复位，DMA，POR，PWM，WDT I/O 数:56 程序存储容量:1MB（1M x 8） 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:128K x 8 电压 - 电源（Vcc/Vdd）:1.98 V ~ 3.8 V 数据转换器:A/D 8x12b，D/A 2x12b 振荡器类型:内部 工作温度:-40°C ~ 85°C（TA） 封装/外壳:64-VFQFN 裸露焊盘 供应商器件封装:64-QFN（9x9） 标准包装:1
EFM32GG230F1024-QFN64 制造商:Energy Micro AS 功能描述:GIANT GECKO MCU - Cut TR (SOS) 制造商:Energy Micro 功能描述:GIANT GECKO MCU 制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32GG230F1024-QFN64T 制造商:Energy Micro AS 功能描述:GIANT GECKO MCU - Trays
EFM32GG230F1024-QFN64-T 制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32-GG230F1024-SK 制造商:Energy Micro AS 功能描述:GIANT GECKO SAMPLE KIT - Bulk
EFM32GG230F1024-T 制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32GG230F512 功能描述:ARM微控制器 - MCU 512KB FL 128KB RAM RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 处理器系列:STM32F373xx 数据总线宽度:32 bit 最大时钟频率:72 MHz 程序存储器大小:256 KB 数据 RAM 大小:32 KB 片上 ADC:Yes 工作电源电压:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LQFP-48 安装风格:SMD/SMT