M16C6K9_15 Datasheet, PDF (167/294 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6K9 Group
LPC Bus Interface
Sequence 1 (basic operation 1)
LPC communication
GateA20 pin
IBF0 flag refresh
IBF interrupt request
Write D1
to 006416
Previous value
Write data
to 006016
Write FF
to 006416
Bit 1 value of the data
No
No
No
No
No
No
Sequence 2 (basic operation 2)
LPC communication
GateA20 pin
IBF0 flag refresh
IBF interrupt request
Write D1
to 006416
Previous value
Write data
to 006016
Write data other
than FF and D1
to 006416
Bit 1 value of the data
No
No
Yes
No
No
Yes
Sequence 3 (basic operation 3)
LPC communication
GateA20 pin
IBF0 flag refresh
IBF interrupt request
Write D1
to 006416
Previous value
Write data
to 006016
Write data
to 006016
Bit 1 value of the data
No
No
Yes
No
No
Yes
Fig.GF-11 GateA20 operation sequence (1)
Rev.1.00 Jun 06, 2003 page 165 of 290