M37702E6BFS Renesas Electronics America, M37702E6BFS Datasheet - Page 284

• 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

unit (CPU), the Hold function is used to generate a timing for transferring the right to use the bus from the
CPU to the external circuit. Fix bit 0 of the port P4 direction register to “0.”
to the HOLD pin and retains this state while the level of the HOLD pin is at “L.” Table 12.4.1 lists the
microcomputer’s state in Hold state.
operate. However, Watchdog timer stops operating.
CONNECTION WITH EXTERNAL DEVICES
12.4 Hold function
12.4 Hold function
When composing the external circuit (DMA) which accesses the bus without using the central processing
In the memory expansion or microprocessor mode, the microcomputer enters Hold state by input of “L” level
In Hold state, the oscillation of the oscillator does not stop. Accordingly, the internal peripheral devices can
Table 12.4.1 Microcomputer’s state in Hold state
Clock
Notes 1: The 7703 Group does not have the HLDA pin.
12–16
Oscillation
E
Pins A
A
Pins HLDA (Note 1), ALE
Pin P4
Pins P4
Watchdog timer
_
CPU
16
/D
0
_____
0
3
_____
2: When this functions as a programmable I/O port.
to A
to A
2
1
/
to P4
output select bit : Bit 7 at address 5E
1
7
, A
23
7
Item
/D
, P5 to P8 (Note 2)
8
/D
7
, R/W, BHE
8
to A
__
15
/D
___
15
,
Operating
Operating
Stopped at “L”
Stopped at “H”
Floating
Outputs “L” level.
In the memory expansion mode:
In the microprocessor mode:
Retains the state when Hold request was accepted.
Stopped
•When clock
•When clock
•This pin outputs clock
request was accepted.
7702/7703 Group User’s Manual
1
1
_____
output select bit = “0,” this pin retains the state when Hold
output select bit = “1,” this pin outputs clock
16
1
.
_____
State
1
.