MC68HC08AZ0 Datasheet, PDF (47/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
EBI
Externally controlled WAIT states
1
1
1
1/2 AC367
Address bus
HC08AZ0
D0
D1
D2
D3
A0
D4
D5
A15 ^D6
D7
$1000 –
CS1 _$FFFF
CS0
WSCLK
Program Memory
1 WAIT-state
D0
D1
D2
$1000–
D3
$FFFF
D4
D5
(60K space)
D6
D7
CS
CS0 = $0000 – $0FFF
CS1 = $1000 – $FFFF, 1WS internal
Peripheral
7 WAIT-states
D7
D6
D5
$0000–
D4
$0FFF
D3
D2
D1
(4K space
less internal
addresses)
D0
CS
A0
A1
Figure 8 Defining WAIT states for Ext addresses below $1000
9-ebi
MOTOROLA
In Figure 8, the user wants to maximize the address space allocated to
the program memory but requires to decode a slow external peripheral
with a 4byte address space. To avoid driving the data bus unnecessarily,
WSCLK is programmed to generate CS0+T4 which will only go low
during T4 whenever the address is within the CSo range as defined by
EBI
For More Information On This Product,
Go to: www.freescale.com
MC68HC08AZ0
45