Z84C9008VSG Zilog, Z84C9008VSG Datasheet - Page 50

• Manufacturer Part Number: Z84C9008VSG
• Description: IC 8MHZ Z80 KIO 84-PLCC
• Manufacturer: Zilog
• Series: Z80r

Specifications of Z84C9008VSG

• Processor Type: Z80
• Features: Serial/Parallel Input/Output, Counter/Timer Circuit
• Speed: 8MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 84-LCC (J-Lead)
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Cpu Speed: 8MHz
• Digital Ic Case Style: LCC
• No. Of Pins: 84
• Supply Voltage Range: 5V
• Operating Temperature Range: 0°C To +70°C
• Svhc: No SVHC (18-Jun-2010)
• Rohs Compliant: Yes
• Base Number: 84
• Clock Frequency: 8MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

30
UM008005-0205
Z80 CPU
User’s Manual
Memory Speed Control
Slow memories can reduce costs for many applications. The WAIT line on
the CPU allows the Z80 to operate with any speed memory. Memory access
time requirements, which are covered in Chapter A3, are most severe
during the M1 cycle instruction fetch. All other memory access cycles
complete in an additional one half clock cycle. Hence, it is sometimes
appropriate to add one wait state to the M1 cycle so slower memories can
be used. Figure 19 is an example of a simple circuit that accomplishes this
objective. This circuit can be changed to add a single wait state to any
memory access as indicated in Figure 20.
Figure 19. Adding One Wait State to an M1 Cycle
CLK
M1
D
C
7474
+5V
S
R
Q
Q
D
C
7474
+5V
+5V
Hardware and Software Implementation Examples
S
R
Q
Q
WAIT
WAIT
CLK
M1
T
1
T
2
M1
T
W
T
3
T
4