HD404374 Datasheet, PDF (26/161 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip A/D Converter

HD404374/HD404384/HD404389/HD404082/HD404084 Series
RAM-mapped register area ($000 to $03F):
• Interrupt control bit area ($000 to $003)
This area consists of bits used for interrupt control. Its configuration is shown in figure 3. Individual
bits can only be accessed by RAM bit manipulation instructions (SEM/SEMD, REM/REMD,
TM/TMD). There are restrictions on access to certain bits. The individual bits and instruction
restrictions are shown in figure 4.
• Special register area ($004 to $01F, $024 to $03F)
This area comprises mode registers and data registers for external interrupts, the serial interface, timers,
A/D converter, etc., and I/O pin data control registers. Its configuration is shown in figures 2 and 5.
These registers are of three kinds: write-only (W), read-only (R), and read/write (R/W). RAM bit
manipulation instructions cannot be used on the other registers.
• Register flag area ($020 to $023)
This area consists of the DTON and WDON flags and interrupt control bits. Its configuration is shown
in figure 3. Individual bits can only be accessed by RAM bit manipulation instructions (SEM/SEMD,
REM/REMD, TM/TMD). There are restrictions on access to certain bits. The individual bits and
instruction restrictions are shown in figure 4.
Memory register (MR) area ($040 to $04F):
In this data area, the 16 memory register digits (MR(0) to MR(15)) can also be accessed by the register-
register instructions LAMR and XMRA. The configuration of this area is shown in figure 6.
Data area ($090 to $23F (HD404374, HD404384, HD404389 Series))
($090 to $0BF (HD404082 Series))
($090 to $13F (HD404084 Series))
Stack area ($3C0 to $3FF):
This is the stack area used to save the contents of the program counter (PC), status flag (ST), and carry flag
(CA) when a subroutine call (CAL or CALL instruction) or interrupt handling is performed. As four digits
are used for one level, the area can be used as a subroutine stack with a maximum of 16 levels. The saved
data and saved status information are shown in figure 6. The program counter is restored by the RTN and
RTNI instructions. The status and carry flags are restored by the RTNI instruction, but are not affected by
the RTN instruction. Any part of the area not used for saving can be used as a data area.
Rev.5.00, Sep.11.2003, page 26 of 161