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WorksheetsDMA Controller _Microprocessor
Total questions: 13
Worksheet time: 7mins
8257 is
DMA Controller
Programmable Input Output
Programmable Interval Timer
Programmable Interrupt Controller
The DMA controller has _______ channels
3
4
5
6
DMA Controller request for control of busses to microprocessor through _____ pin
HLDA
HOLD
RQ/GT
READY
The DMA controller sends Hold request (HRQ) to the CPU and waits for the CPU to assert the _____
HLDA
HOLD
RQ/GT
READY
Each channel of DMA Controller can transfer data maximum up to _____
12 kb
64 kb
32 kb
128 kb
Each channel of DMA Controller can perform
read transfer
Write transfer
verify transfer
All of the above
These are the four individual channel DMA request inputs, which are used by the peripheral devices for using DMA services
DRQ0−DRQ3
DACKo − DACK3
Do − D7
Ao - A3
These are the active-low DMA acknowledge lines, which updates the requesting peripheral about the status of their request by the CPU.
DRQ0−DRQ3
DACKo − DACK3
Do − D7
Ao - A3
It generates '______ signal to the peripheral device that 128 bytes have been transferred.
DRQ0−DRQ3
DACKo − DACK3
MARK
Ao - A3
_______ is designed by Intel to transfer data at the fastest rate. It allows the device to transfer the data directly to/from memory without any interference of the CPU.
DMA Controller
Programmable Input Output
Programmable Interval Timer
Programmable Interrupt Controller
_____ when enabled, permits block chaining operations, without immediate software intervention between blocks. In this mode, channel 2 parameters (DMA starting address, terminal count and DMA transfer mode) are initialized as usual for the first data block.
Auto load Mode
Rotating Priority mode
Fixed Priority mode
Status register
If the _______ is set, a channel is disabled after the terminal count (TC) output goes high,
Auto load Mode
Rotating Priority mode
Fixed Priority mode
TC stop bit
It generates '______ signal to the peripheral device that 128 bytes have been transferred.
DRQ0−DRQ3
DACKo − DACK3
MARK
Ao - A3
