UPD784216 View Datasheet(PDF) - NEC => Renesas Technology

Part Name

Description

Manufacturer

UPD784216

16-BIT SINGLE-CHIP MICROCONTROLLERS

NEC => Renesas Technology 

µPD78F4216A, 78F4218A, 78F4216AY, 78F4218AY

5. INTERNAL MEMORY SIZE SWITCHING REGISTER (IMS)

IMS is a register that is set by software and is used to specify a part of the internal memory that is not to be used.

By setting this register, the internal memory of the µPD78F4218AY can be mapped identically to that of a mask ROM

version with a different internal memory (ROM and RAM) capacity.

IMS is set with an 8-bit memory manipulation instruction.

RESET input sets IMS to FFH.

(1) µPD78F4216A, 78F4216AY

Figure 5-1. Internal Memory Size Switching Register (IMS) Format

Address: 0FFFCH

After reset: FFH W

7

6

5

4

3

IMS

1

1

ROM1

ROM0

1

2

1

0

1

RAM1

RAM0

ROM1

0

0

1

1

ROM0

0

1

0

1

48 KB

64 KB

96 KB

128 KB

Internal ROM Capacity Selection

RAM1

0

0

1

1

RAM0

0

1

0

1

3,072 bytes

4,608 bytes

6,114 bytes

7,680 bytes

Peripheral RAM Capacity Selection

Caution IMS is not provided on the mask ROM versions (µPD784214A, 784215A, 784216A, µPD784214AY,

784215AY, and 784216AY).

Table 5-1 shows the IMS setting values to make the memory mapping the same as that of the mask ROM

versions.

Table 5-1. Setting Value of Internal Memory Size Switching Register (IMS)

Target Mask ROM Version

µPD784214A, 784214AY

µPD784215A, 784215AY

µPD784216A, 784216AY

IMS Setting Value

ECH

FDH

FFH

20

Data Sheet U14125EJ1V0DS00

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