MTV230M64
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FUNCTIONAL DESCRIPTIONS
1. 8051 CPU Core
The CPU core of MTV230M64 is compatible with the industry standard 8051, which includes 256 bytes RAM,
Special Function Registers (SFR), two timers, five interrupt sources and serial interface. The CPU core fetches
its program code from the 64K bytes Flash in MTV230M64. It use Port0 and Port2 to access the “external
special function register” (XFR) and external auxiliary RAM (AUXRAM).
The CPU core can run at double rate when FclkE is set. Once the bit is set, the CPU runs as if a 24MHz X’tal is
applied on MTV230M64, but the peripherals (IIC, DDC, H/V processor …) still run at the original frequency.
Note: All registers listed in this document reside in 8051’s external RAM area (XFR). For internal RAM memory
map please refer to 8051 spec.
2. Memory Allocation
2.1 Internal Special Function Registers (SFR)
The SFR is a group of registers that are the same as standard 8051.
2.2 Internal RAM
There are total 256 bytes internal RAM in MTV230M64, the same as standard 8052.
2.3 External Special Function Registers (XFR)
The XFR is a group of registers allocated in the 8051 external RAM area F00h - FFFh. These registers are used
for OSD control or other special function. Program can use "MOVX" instruction to access these registers.
2.4 Auxiliary RAM (AUXRAM)
There are total 768 bytes auxiliary RAM allocated in the 8051 external RAM area 800h - AFFh. Program can
use "MOVX" instruction to access the AUXRAM.
800h
AFFh
F00h
FFFh
XFR
Accessible by
indirect external
RAM addressing
(Using MOVX
instruction)
AUXRAM
Accessible by
indirect external
RAM addressing
(Using MOVX
instruction
00h
7Fh
80h
FFh
Internal RAM
Accessible by
indirect
addressing only
(Using
MOV A,@Ri
instruction)
Internal RAM
Accessible by
direct and indirect
addressing
SFR
Accessible by
direct addressing