HD4046212RFS datasheet(13/157 Pages) RENESAS

13 / 157 page

HD404629R Series

RAM Memory Map

The MCU contains a 1,876-digit

× 4-bit RAM area consisting of a memory register area, an LCD data area,

a data area, and a stack area. In addition, an interrupt control bits area, special register area, and register

flag area are mapped onto the same RAM memory space as a RAM-mapped register area outside the above

areas. The RAM memory map is shown in figure 2 and described below.

RAM-Mapped Register Area ($000–$03F):

• Interrupt Control Bits Area ($000–$003)

This area is used for interrupt control bits (figure 3). These bits can be accessed only by RAM bit

manipulation instructions (SEM/SEMD, REM/REMD, and TM/TMD). However, note that not all the

instructions can be used for each bit. Limitations on using the instructions are shown in figure 4.

• Special Function Register Area ($004–$01F, $024–$03F)

This area is used as mode registers and data registers for external interrupts, serial interface,

timer/counters, LCD, A/D converter, and as data control registers for I/O ports. The structure is shown

in figures 2 and 5. These registers can be classified into three types: write-only (W), read-only (R), and

read/write (R/W). The SEM, SEMD, REM, and REMD instructions can be used for the LCD control

• Register Flag Area ($020–$023)

• This area is used for the DTON, WDON, and other register flags and interrupt control bits (figure 3).

These bits can be accessed only by RAM bit manipulation instructions (SEM/SEMD, REM/REMD, and

TM/TMD). However, note that not all the instructions can be used for each bit. Limitations on using

the instructions are shown in figure 4.

HD4046212RFS Datasheet(PDF) 13 Page - Renesas Technology Corp