Specifications

Data Memory
3-15 Memory
- The scratch-pad RAM block (B2) includes 32 words of DARAM that pro-
vide for variable storage without fragmenting the larger RAM blocks,
whether internal or external. This RAM block supports dual-access opera-
tions and can be addressed via any data-memory addressing mode.
Table 3–1 shows the address map of data page 0.
Table 3–1. Data Page 0 Address Map
Address Name Description
0000h–0003h – Reserved
0004h IMR Interrupt mask register
0005h – Reserved
0006h IFR Interrupt flag register
0023h–0027h – Reserved
002Bh–002Fh – Reserved for test/emulation
0060h–007Fh
B2 Scratch-pad RAM (DARAM B2)
Data Memory Configuration
Two factors that contribute to the configuration of data memory are:
- CNF bit. The CNF bit (bit 12) of status register ST1 determines whether
the on-chip DARAM B0 is mapped to data space or program space.
J CNF = 1. B0 is used for program space.
J CNF = 0. B0 is used for data space.
At reset, B0 is mapped into data space (CNF = 0).
3.5.1 Global Data Memory
Note:
Global Data Memory is not available in ’240x. Hence, the global memory al-
location register (GREG) is a reserved location and should not be accessed.