Z16M1720ASG1868 Zilog, Z16M1720ASG1868 Datasheet - Page 157

• Manufacturer Part Number: Z16M1720ASG1868
• Description: IC PCMCIA INTERFACE 100-VQFP
• Manufacturer: Zilog

Specifications of Z16M1720ASG1868

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 100-LQFP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

UM008101-0601
Z80 DMA and Z80 SIO Example
Figure 54.
A common DMA application is performing data transfers over a serial data
link. The Z80 SIO peripheral is used to interface to the link, providing
conversion between serial and parallel data formats, synchronization, and
other functions.
Comparing the efficiency of interrupt driven and DMA data transfers
requires examination of the event sequences during the brief time intervals
in which the SIO needs a character (byte) transfer. Most of the time the SIO
is busy transmitting or receiving message bits and requires no service.
The SIO must be programmed to drive its WAIT/RDY line as a RDY signal
to the DMA, which is programmed for active-Low RDY in Byte mode.
DMA.HAS.BUS
DMA.CE
CTC.CE
SIO.CE
PIO.CE
CARD.IEO
CARD.IEI
IORQ
RD
M1
Data Bus Buffer Control Example
System Data Bus
ON.CARD.ENABLE
RD
DMA.WRITE
DIR
47LS
245
EN
ON.CARD.INT ACK
DRIVE.DATA.OUT
On-Card Data Bus
ON.CARD.READ
<   % 2 7 2 G T K R J G T C N U
Direct Memory Access
7 U G T / C P W C N