ST2202A
10. CHIP-SELECT LOGIC (CSL)
TheꢀST2202ꢀbuildsꢀinꢀoneꢀchipꢁselectꢀsignalꢀ(
)ꢀforꢀ
singleꢀdeviceꢀofꢀ16Mꢀbytesꢀatꢀ
ꢀ possible.ꢀTheꢀaddressꢀ
CS0
CS5
embeddedꢀ256KꢀbytesꢀmaskꢀROMꢀandꢀsixꢀchipꢁselectꢀsignalsꢀ
multiplexedꢀwithꢀPD5~0ꢀofꢀPortꢁDꢀwhichꢀareꢀusedꢀtoꢀselectꢀ
externalꢀdevicesꢀonꢀtheꢀaddressꢀandꢀdataꢀbus.ꢀThereꢀareꢀtwoꢀ
optionsꢀforꢀtheꢀfirstꢀ256Kꢀbytesꢀmemoryꢀwhichꢀareꢀcontrolledꢀbyꢀ
MMDꢀpin.ꢀTieꢀMMDꢀtoꢀgroundꢀtoꢀselectꢀnormalꢀmodeꢀandꢀ
enableꢀinternalꢀROMꢀforꢀtheꢀfirstꢀ256Kꢀbytesꢀmemory.ꢀConnectꢀ
MMDꢀtoꢀchipꢁselectꢀofꢀanꢀexternalꢀdeviceꢀtoꢀselectꢀemulationꢀ
modeꢀandꢀdisableꢀinternalꢀROM.ꢀAfterꢀresetꢀcycles,ꢀMMDꢀ
rangeꢀofꢀ
ꢀ ofꢀhigherꢀnumberꢀfollowsꢀtheꢀrangeꢀofꢀpreviousꢀ
CSx
oneꢀofꢀlowerꢀnumber.ꢀReferꢀtoꢀTABLEꢀ10ꢁ2ꢀforꢀconfigurationsꢀofꢀ
allꢀchipꢁselectsꢀinꢀdifferentꢀmodes.ꢀ
ꢀ
Note:ꢀWriteꢀ“1”ꢀtoꢀbitꢀofꢀportꢀdirectionꢀcontrolꢀ
registerꢀPCD,ꢀthenꢀtoꢀbitꢀofꢀportꢀ
functionꢁselectꢀregisterꢀPFDꢀtoꢀactivateꢀtheꢀ
designatedꢀchipꢁselectꢀsignal.
changesꢀtoꢀanꢀoutputꢀandꢀoutputsꢀchipꢁselectꢀsignalꢀ
.ꢀ
CS0
ReferꢀtoꢀFIGUREꢀ10ꢁ1ꢀforꢀtwoꢀconnectionsꢀofꢀdifferentꢀmodes.ꢀ
ꢀ
TwoꢀbitsꢀCSM[1:0]ꢀofꢀportꢀmiscellaneousꢀregisterꢀ(PMCR)ꢀ
selectꢀfourꢀmodesꢀofꢀCSLꢀwhichꢀdefineꢀtheꢀmemoryꢀsizeꢀofꢀ
eachꢀexternalꢀchipꢁselect.ꢀIfꢀCSM0ꢀequalsꢀ“1”,ꢀchipꢁselectꢀ
signalꢀ
ꢀ changesꢀtoꢀbeꢀaddressꢀsignalꢀA23ꢀtoꢀmakeꢀoneꢀ
CS6
ꢀ
ꢀ
ꢀ
A. Normal Mode
B. Emulation Mode
FIGURE 10-1 Connections Of MMD/
CS0
ꢀ
ꢀ
TABLE 10-2 Memory Configurations Of Chip-selects
Externalꢀ
Firstꢀ256Kꢀ Chipꢁselectꢀ
Modesꢀ
TotalꢀSupportꢀ
MemoryꢀSizeꢀ
MemoryꢀRangeꢀandꢀSizeꢀofꢀChipꢁselectsꢀ
,ꢀ
CS0
CSM[1:0]
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
/A23ꢀ
CS6
CS1
CS2
CS3
CS4
CS5
MMD/
ꢀ
CS0
$1000000~ꢀ$1800000~ꢀ
$17FFFFFꢀ $1FFFFFFꢀ
0ꢀ0ꢀ
$0400000~ꢀ$0500000~ꢀ$0600000~ꢀ$0800000~ꢀ
$04FFFFFꢀ $05FFFFFꢀ $07FFFFFꢀ $0FFFFFFꢀ
(
8Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ
28M + 256K
ꢀ
Bytesꢀ
$1000000~ꢀ
$1FFFFFFꢀ
(
1Mꢀbytes)ꢀ (1Mꢀbytes)ꢀ (2Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ
0ꢀ1ꢀ
1ꢀ0ꢀ
1ꢀ1ꢀ
A23ꢀ
$0000000~ꢀ
$003FFFFꢀ
(
16Mbytes)ꢀ
ꢀ
$2000000~ꢀ$2800000~ꢀ
$27FFFFFꢀ $2FFFFFFꢀ
(
256Kbyte)ꢀ
$0400000~ꢀ$0800000~ꢀ$1000000~ꢀ$1800000~ꢀ
$07FFFFFꢀ $0FFFFFFꢀ $17FFFFFꢀ $1FFFFFFꢀ
(
8Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ
44M + 256K
ꢀ
Bytesꢀ
$2000000~ꢀ
$2FFFFFFꢀ
(
4Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ (8Mꢀbytes)ꢀ
A23ꢀ
(
16Mbytes)ꢀ
ꢀ
Verꢀ2.5ꢀ
19
/75
ꢀ
9/16/2008ꢀ
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
