Fujitsu FR81S User Manual
CHAPTER 36: EXTERNAL BUS INTERFACE
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : EXTERNAL BUS INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
15
[bit11, bit10] CSWR[1:0] (CSnX to WRnX setup cycle) : CSnX to WRnX Setup Cycle
CSWR[1:0] configures the write access CSnX to WRnX setup cycles which set the period until WRnX is
asserted after CSnX is asserted.
In order to correctly establish the protocol when address/data multiplex bus is configured (ACR.BSTY=1),
set the AWR parameters to satisfy the following conditions.
ACS + CSRD
≥
1 and ACS + CSWR
≥
1
CSWR[1:0]
CSnX → WRnX Setup extension cycle
00
0 cycle (AWR0 Initial value)
01
1 cycle
10
2 cycles
11
3 cycles
[bit9, bit8] WRCS[1:0] (WRnX to CSnX hold cycle) : WRnX to CSnX Hold Cycle
WRCS[1:0] configures the write access WRnX to CSnX hold cycles which set the period until CSnX is
negated after WRnX is negated.
WRCS[1:0]
WRnX → CSnX hold extension cycle
00
0 cycle (AWR0 Initial value)
01
1 cycle
10
2 cycles
11
3 cycles
[bit7, bit6] ADCY[1:0] (ADdress CYcle) : Address Output Extension Cycle Count
ADCY[1:0] sets the number of extension cycles for outputting addresses to the data bus during access to CS
areas configured with address/data multiplexed bus type. The settings of these bits are only valid when the
bus type is set to address/data multiplexed.
In order to correctly establish the protocol when ADCY is set to 1 or higher, set the AWR parameters to
satisfy the following conditions.
ADCY + 1
≤
ACS + CSRD and ADCY + 1
≤
ACS + CSWR
ADCY[1:0]
Number of address output extension cycles during address/data
multiplexing
00
0 cycle (AWR0 Initial value)
01
1 cycle
10
2 cycles
11
3 cycles
MB91520 Series
MN705-00010-1v0-E
1214