Please refer to page 2-3 of your DSP text Book
Program counter (PC).
The C24x has a 16-bit program counter (PC) that addresses internal and
external program memory when fetching instructions
1.CNF: On-chipDARAM configuration bit. This bit determines whether
reconfigurable dual-access RAM blocks are mapped to data space or to
program space. The CNF bit may be modified
by the SETC CNF, CLRC CNF,
0 = Reconfigurable dual-access RAM blocks are mapped to data space
1 = Reconfigurable dual-access RAM blocks are mapped to program space
2. MP/MC pin.
The level on the MP/MC pin determines whether program instructions are
read from on-chip flash/ROM or external memory:
MP/MC = 0. The device is configured in microcomputer mode. The onchip
ROM/flash EEPROM is accessible. The device fetches the reset vector from
on-chip memory. Accesses to program memory
addresses 0000h–1FFFh will be made to on-chip memory.
MP/MC = 1. The device is configured in microprocessor mode.
The device fetches the reset vector from external memory. Accesses to
program memory addresses 0000h–1FFFh will be made to off-chip
memory.
3. Using Immediate /Direct /Indirect Addressing with ADD
Immediate addressing mode.
Short-immediate addressing. Instructions that use short-immediate
addressing take an 8-bit, 9-bit, or 13-bit constant as an operand.
Short-immediate instructions require a single instruction word, with the
constant embedded in that word.
Long-immediate addressing. Instructions that use long-immediate
addressing take a 16-bit constant as an operand and require two instruction
words. The constant is sent as the second instruction
Direct
Addressing
INDirect
4. Input
Addressing
/ Output space
Control signal: /IS (/DS, /PS)
Interface signal: A0-A15, D0-D15, W/R, WE
IN
DAT7,0FFFEh
;Read data to data memory
; from external device on port 65534.
OUT DAT7,0FFFFh ; Write data from data memory
; to external device on port 65535.
5. the repeat (RPT): instruction to determine how many times the instruction
following RPT is repeated
6. RPT/BANZ
.