Z0847006PSG Zilog, Z0847006PSG Datasheet - Page 180

• Manufacturer Part Number: Z0847006PSG
• Description: IC 6MHZ Z80 NMOS DART 40-DIP
• Manufacturer: Zilog
• Series: Z80r

Specifications of Z0847006PSG

• Processor Type: Z80
• Features: Dual Channel Asynchronous Receiver/Transmitter (DART)
• Speed: 6MHz
• Voltage: 5V
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.620", 15.75mm)
• Mounting Style: Through Hole
• Cpu Speed: 6MHz
• Digital Ic Case Style: DIP
• No. Of Pins: 40
• Supply Voltage Range: 5V
• Operating Temperature Range: 0°C To +70°C
• Svhc: No SVHC (18-Jun-2010)
• Base Number: 847006
• Rohs Compliant: Yes
• Clock Frequency: 6MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

UM008101-0601
<   % 2 7 2 G T K R J G T C N U
7 U G T / C P W C N
BUSREQ
Bus Release on Match
When the DMA is programmed to stop (release the bus) on match in Burst
or Continuous modes, a match causes BUSREQ to go inactive on the next
DMA operation, for example, at the end of the next read in search-only,
simultaneous transfer/searches, or at the end of the following write in
sequential transfer or transfer/searches (Figure 68).
Figure 68.
Because of the pipelining scheme, matches are determined while the next
DMA read or write is being performed. Table 12 lists the number of bytes
transferred in any class or mode.
The RDY line can go inactive after the matching operation begins without
affecting this bus-release timing. However, the time at which RDY goes
inactive can affect the number of bytes transferred, as described in Table 11
and Figure 32.
Bus Release on Not Ready
Burst mode, when RDY goes inactive, causes BUSREQ to go High on the
next rising edge of CLK after the completion of its current byte operation,
for example, at the end of the current read in search-only, simultaneous
transfer/search, or at the end of the following write in sequential transfer/
RDY
CLK
Active
Inactive
Bus Release on Match (Burst and Continuous Modes)
Read in
Byte n
Match Found
on Byte n
Byte n+1
Read in
and
Direct Memory Access
DMA
Inactive