z80189 ZiLOG Semiconductor, z80189 Datasheet - Page 106

• Manufacturer Part Number: z80189
• Description: Z80180, Z8s180, Z8l180 Mpu Operation
• Manufacturer: ZiLOG Semiconductor

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There is an additional feature disc for DMA interrupt request by DMA
END. Each channel has the following additional specific capabilities:
Channel 0
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Channel 1
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DMAC Registers
Each channel of the DMAC (channel 0, 1) contains three registers
specifically associated with that channel.
DREQ Input
Level- and edge-sense DREQ input detection are selectable.
TEND Output Used to indicate DMA completion to external devices.
Transfer Rate
Each byte transfer occurs every 6 clock cycles. Wait States can be
inserted in DMA cycles for slow memory or I/O devices. At the
system clock (f) = 6 MHz, the DMA transfer rate is as high as 1.0
megabytes/second (no Wait States).
Memory to memory
Memory to I/O
Memory to memory mapped I/O transfers.
Memory address increment, decrement, no-change
Burst or cycle steal memory to/from memory transfers
DMA to/from both ASCI channels
Higher priority than DMAC channel 1
Memory to/from I/O transfer
Memory address increment, decrement
Family MPU User Manual
UM005003-0703
Z8018x
91