EM77950
BB Controller
7 Function Description
7.1 Special Purpose Registers
The special purpose registers are function-oriented registers used by the CPU to
access memory, record execution results, and carry out the desired operation. The
functions of the registers related to the core are described in the following subsections
7.1.1 Accumulator – ACC
Internal data transfer operation, or instruction operand holding usually involves the
temporary storage function of the Accumulator, which is not an addressable register.
7.1.2 Indirect Addressing Contents – IAC0 (0x00), and IAC1 (0x09)
The contents of R0 and R9 are implemented as indirect addressing pointers if any
instruction uses R6 and R8 as registers.
7.1.3 High Byte Program Counter HPC (0x01) and Low Byte
Program Counter LPC (0x02)
Program Counter (PC) is composed of registers HPC and LPC.
PC and the hardware stacks are 14 bits wide.
The structure is depicted in Fig. 6-1.
Generates 12K × 16 on-chip ROM addresses to the corresponding program
memory (ROM).
Product Specification (V1.0) 10.09.2007
(This specification is subject to change without further notice)
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ELAN [ ELAN MICROELECTRONICS CORP ]
