
I / O H U B M O D U L E
DMA controller
366
Hardware Reference NS9215
31 March 2008
For transmit channels. CPU sets the F bit after the data is written to a buffer.
The DMA controller clears this bit as each buffer is read from external memory.
If the DMA controller ever finds that this bit is not set when the buffer
descriptor is read, the NRIP bit is set in the Interrupt Status register and the
DMA controller stops immediately and goes to the ERROR state. The CPU must
clear the CE bit to restore the DMA.
For receive channels, hardware sets the F bit after data is written to a buffer.
The CPU must clear the F bit after all data has been read from the buffer. If
the DMA controller ever finds that this bit is not clear when the buffer
descriptor is read, the NRIP bit is set in the Interrupt Status register and the
DMA controller stops immediately.
The DMA controller must be soft reset after the buffer descriptor problem
has been solved.
Control[11:0]
These bits are not used.
Status[15:0]
The status depends on the module, as defined in the next tables.
Note:
In direct mode, the status can be read from the Direct Mode RX Status FIFO.
UART
Bits
Description
15:7
Reserved
6:5
01
Error; bits 3:0 indicate the error type
bit 4: Reserved
bit 3: Receiver overflow, should never occur in a properly configured system
bit 2: Parity error
bit 1: Framing error
bit 0: Break condition
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...