Z80 datasheet(323/330 Pages) ZILOG

323 / 330 page

Z80 CPU Peripherals

User Manual

UM008101-0601

Serial Input/Output

303

The Z80 DMA controller circuit is used with Z80 SIO/2 to transmit the

reformatted data at high speed with the required protocol. The high-speed

modem provides the transmit clock for this channel. The Z80 CTC counter-

timer circuit supplies the transmit and receive clocks for the low-speed

lines and is also used as a time-out counter for various functions.

Z80 SIO/1 controls local or remote terminals. A single intelligent terminal

is placed within the dashed lines. The terminal employs a Z80 SIO to

communicate to the data concentrator on one channel while providing the

interface to a line printer over its second channel. The intelligent terminal

could be designed to operate interactively with the operator.

Depending on the software and hardware capabilities built into this system,

the data concentrator can employ store-and-forward or hold-and-forward

methods for regulating information traffic between slow terminals and the

high-speed remote processor. If the high-speed channel is provided with a

dial-out option, the channel can be connected to a number of remote

processors over a switched line.

Z80 Datasheet(PDF) 323 Page - Zilog, Inc.