ez80190 ZiLOG Semiconductor, ez80190 Datasheet - Page 67

• Manufacturer Part Number: ez80190
• Description: Ez80190 Microprocessor
• Manufacturer: ZiLOG Semiconductor

PS006613-0306
Wait States
ADDR[23:0]
DATA[7:0]
(input)
INSTRD
MREQ
For each of the 4 available Chip Selects, programmable WAIT states can be
inserted to provide external devices with additional clock cycles to complete their
read and write operations. The number of WAIT states for a particular Chip Select
is controlled by the 3-bit field CSx_wait (CSx_CTL[7:5]). The Chip Selects can be
independently programmed to provide 0 to 7 WAIT states. The WAIT states idle
the CPU for the specified number of system clock cycles. An example of WAIT
state operation is illustrated in
added. It causes the instruction read operation to use an additional clock cycle.
WAIT is an internal signal used by the eZ80190 device and is illustrated in
Figure 9
X
WAIT
OUT
CSx
RD
for informational purposes only.
Figure 9. Wait State Operation Example
T
CLK
PRELIMINARY
Figure
9. In this example, a single WAIT state is
eZ80190 Product Specification
Chip Selects and Wait States
53