M37702E6BFS Renesas Electronics America, M37702E6BFS Datasheet - Page 281

• Manufacturer Part Number: M37702E6BFS
• Description: EPROM MCU/8BIT CMOS EMULATION CH
• Manufacturer: Renesas Electronics America

Specifications of M37702E6BFS

• Accessory Type: Emulator EPROM MCU
• For Use With/related Products: 7702
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

12.3 Ready function
Ready function provides a function to facilitate access to external devices that require a long access time.
Fix bit 1 of the port P4 direction register to “0.”
By supplying “L” level to the RDY pin in the memory expansion or microprocessor mode, the microcomputer
enters Ready state and retains this state while the RDY pin is at “L” level. Table 12.3.1 lists the microcomputer’s
state in Ready state.
In Ready state, the oscillator’s oscillation does not stop, so that the internal peripheral devices can operate.
Ready function is valid for the internal and external areas.
Table 12.3.1 Microcomputer’s state in Ready state
Watchdog timer
Clock
Notes 1: The 7703 Group does not have the HLDA pin.
Oscillation
Pins A
A
R/W, BHE, HLDA (Note 1),
ALE
Pins P4
P5 to P8 (Note 2)
P4
CPU
15
__
2
/D
/
,
1
15
____
2: When this functions as a programmable I/O port.
0
, A
1
3
to A
output select bit : Bit 7 at address 5E
to P4
16
/D
Item
_____
7
, A
0
7
to A
,
8
/D
CONNECTION WITH EXTERNAL DEVICES
8
23
to
/D
7
, E,
_
____
Operating
Stopped at “L”
Retains the state when Ready request was accepted.
In the memory expansion mode:
In the microprocessor mode:
Operating
•When clock
•When clock
•This pin outputs clock
Ready request was accepted.
7702/7703 Group User’s Manual
1
1
_____
output select bit = “1,” this pin outputs clock
output select bit = “0,” this pin retains the state when
____
16
1
.
State
12.3 Ready function
1
.
12–13