Mitsubishi DS5000TK, DS907x SIP manual Peripheral Enables in the Data Memory MAP ±7

USER'S GUIDE

On occasion, a memory mapped peripheral is needed that interfaces directly to an 8051 multiplexed bus. When this occurs, MOVX instructions can be forced to use the Expanded bus in any mode with the EXBS bit (RPCTL.5). Setting this bit to a logic one forces all

MOVX instructions to the Expanded bus. While EXBS=1, the entire 64K data memory map is accessed in this way. Clearing EXBS will cause the microcontrol- ler to revert to its selected configuration. In most sys- tems, the EXBS bit will not be used.

PERIPHERAL ENABLES IN THE DATA MEMORY MAP Figure 4±7

64K

0

PES=1

PE4

PE3

PE2

PE1

DATA

MEMORY

FFFFh

BFFFh

7FFFh

3FFFh

DS5001/DS5002 Memory Map Control

Like the DS5000, the DS5001/DS5002 uses Special Function Registers to control the memory map. The memory control functions include the Partition, Range, Partition Mode (PM), Expanded Bus Select (EXBS), Pe- ripheral Enable Select (PES) and Access Enable (AE ± discussed below). The Partition and Range can be se- lected using the Bootstrap Loader discussed in a later section. In addition, the Partition can be selected or mo- dified by the application software by writing to the

MCON register. PES is normally used by software and is also controlled by the MCON register. The MCON is documented in the SFR summary, but also appears here for convenience. The Range is controlled by a combination of MCON and RPCTL bits. In addition, the EXBS and AE are controlled using the RTPCL register. As not all of the RPCTL bits pertain to memory control, the relevant bits are described below. RPCTL is fully documented in the SFR summary.

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