Mitsubishi DS907x SIP, DS5000TK manual RG1 RG0 Range CE1 Access CE2 Access

USER'S GUIDE

a Partitionable mode (PM=0), the DS5001 can use up to 64K x 8 SRAM for program and data on its Byte±wide bus. It can partition this area into program and data segments on 4K boundaries. The 64K memory space would consist of two 32K x 8 SRAMs. Each is accessed

by a separate chip enable (CE1 and CE2), but the mi- crocontroller automatically decodes which is needed. While the DS5001 can use between one 8K x 8 SRAM and 4 32K x 8 SRAMs, it does not automatically know

which configuration is used. The Range function deter- mines how much total memory is connected to the Byte±wide bus. The user must identify the total RAM size using the Range bits RG1 and RG0. RG1 is lo- cated at MCON.3 and RG0 is located at RPCTL.0. These Range bits are selected during the Bootstrap Loading process and can not be modified by the ap- plication software. The Table below shows the Range values that can be selected when PM=0 (Partitionable).

RG1	RG0	RANGE	CE1 ACCESS	CE2 ACCESS
1	1	64K	0000±7FFFh	8000±FFFFh
1	0	32K	0000±7FFFh	NA
0	1	16K	0000±1FFFh	2000h±3FFFh
0	0	8K	0000±1FFFh	NA

The total RAM space is partitionable, regardless of which Range is selected. This contrasts with the DS5000 that allowed partitioning of CE1 only. The Partition table is shown below. PA3±0 are the four MSBs of the MCON register (MCON.7±4). Note that the Parti- tion values do not scale depending on Range. That is, if

a Range of less than 64K is selected, then the partition settings above the Range should not be unused. The microcontroller automatically decodes which RAM to enable, and uses the Partition to decide if this is pro- gram memory or data memory.

PA3	PA2	PA1	PA0	PARTITION	BYTE±WIDE BUS MEMORY MAP
0	0	0	0	0000h	0K PROGRAM, DATA = RANGE
0	0	0	1	1000h	4K PROGRAM, DATA = RANGE ± 4K
0	0	1	0	2000h	8K PROGRAM, DATA = RANGE ± 8K
0	0	1	1	3000h	12K PROGRAM, DATA = RANGE ± 12K
0	1	0	0	4000h	16K PROGRAM, DATA = RANGE ± 16K
0	1	0	1	5000h	20K PROGRAM, DATA = RANGE ± 20K
0	1	1	0	6000h	24K PROGRAM, DATA = RANGE ± 24K
0	1	1	1	7000h	28K PROGRAM, DATA = RANGE ± 28K
1	0	0	0	8000h	32K PROGRAM, DATA = RANGE ± 32K
1	0	0	1	9000h	36K PROGRAM, 28K DATA
1	0	1	0	A000h	40K PROGRAM, 24K DATA
1	0	1	1	B000h	44K PROGRAM, 20K DATA
1	1	0	0	C000h	48K PROGRAM, 16K DATA
1	1	0	1	D000h	52K PROGRAM, 12K DATA
1	1	1	0	E000h	56K PROGRAM, 8K DATA
1	1	1	1	FFFFh	64K PROGRAM, 0K DATA

Figure 4±5 illustrates the functional memory map of a DS5001 series device in Partitionable mode. Note that like the DS5000, any access that does not correspond

to a Byte±wide bus location is routed to the Expanded bus Ports 0 and 2.

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