Z0847006PSG Zilog, Z0847006PSG Datasheet - Page 219

• 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

APPLICATIONS
UM008101-0601
Extending The Interrupt Daisy-chain
Figure 13.
Without external logic, a maximum of four Z80 PIO devices may be daisy-
chained into a priority interrupt structure. This limitation allows the inter-
rupt enable status (IEO) to ripple through the entire daisy-chain between
the beginning of M1 and the beginning of IORQ during an interrupt
acknowledge cycle. The interrupt enable status cannot change during M1,
therefore, the vector address returned to the CPU is assured to be from the
highest priority device that requested an interrupt.
+
+
+
+
+
3. Port 1B1 interrupts, suspends servicing of Port 2A.
4. Port 1B service routine complete, ‘RETI’ issued, Port 2A service resumed.
1. Priority interrupt daisy chain before any interrupt occurs.
2. Port 2A requests an interrupt and is Acknowledged.
5. Second ‘RETI’ instruction issued on completion of Port 2A service routine.
HI
HI
HI
HI
HI
Highest Priority Channel
IEI
IEI
IEI
IEI
IEI
Port 1A
Daisy-Chain Interrupt Servicing
IEO
IEO
IEO
IEO
IEO
HI
HI
HI
HI
HI
Service Complete
Under Service
IEI
IEI
IEI
IEI
IEI
Port 2A
IEO
IEO
IEO
IEO
IEO
HI
HI
LO
HI
HI
Service Suspended
Service Resumed
Service Complete
IEI
IEI
IEI
IEI
IEI
Under Service
Port 1B
IEO
IEO
IEO
IEO
IEO
<   % 2 7 2 G T K R J G T C N U
HI
LO
LO
LO
HI
Parallel Input/Output
IEI
IEI
IEI
IEI
IEI
7 U G T / C P W C N
Port 2B
IEO
IEO
IEO
IEO
IEO
HI
LO
LO
LO
HI