C8051F02X Datasheet, PDF (24/272 Pages) Silicon Laboratories – 8K ISP FLASH MCU Family

C8051F020/1/2/3
1.2. On-Chip Memory
The CIP-51 has a standard 8051 program and data address configuration. It includes 256 bytes of data RAM, with the
upper 128 bytes dual-mapped. Indirect addressing accesses the upper 128 bytes of general purpose RAM, and direct
addressing accesses the 128 byte SFR address space. The lower 128 bytes of RAM are accessible via direct and indi-
rect addressing. The first 32 bytes are addressable as four banks of general purpose registers, and the next 16 bytes
can be byte addressable or bit addressable.
The CIP-51 in the C8051F020/1/2/3 MCUs additionally has an on-chip 4k byte RAM block and an external memory
interface (EMIF) for accessing off-chip data memory. The on-chip 4k byte block can be addressed over the entire 64k
external data memory address range (overlapping 4k boundaries). External data memory address space can be
mapped to on-chip memory only, off-chip memory only, or a combination of the two (addresses up to 4k directed to
on-chip, above 4k directed to EMIF). The EMIF is also configurable for multiplexed or non-multiplexed address/data
lines.
The MCU’s program memory consists of 64k bytes of FLASH. This memory may be reprogrammed in-system in
512 byte sectors, and requires no special off-chip programming voltage. The 512 bytes from addresses 0xFE00 to
0xFFFF are reserved for factory use. There is also a single 128 byte sector at address 0x10000 to 0x1007F, which
may be useful as a small table for software constants. See Figure 1.7 for the MCU system memory map.
Figure 1.7. On-Chip Memory Map
PROGRAM/DATA MEMORY
(FLASH)
0x1007F
0x10000
0xFFFF
0xFE00
0xFDFF
Scrachpad Memory
(DATA only)
RESERVED
0xFF
0x80
0x7F
FLASH
(In-System
Programmable in 512
Byte Sectors)
0x30
0x2F
0x20
0x1F
0x00
0x0000
0xFFFF
DATA MEMORY (RAM)
INTERNAL DATA ADDRESS SPACE
Upper 128 RAM
(Indirect Addressing
Only)
Special Function
Register's
(Direct Addressing Only)
(Direct and Indirect
Addressing)
Bit Addressable
General Purpose
Registers
Lower 128 RAM
(Direct and Indirect
Addressing)
EXTERNAL DATA ADDRESS SPACE
Off-chip XRAM space
0x1000
0x0FFF
0x0000
XRAM - 4096 Bytes
(accessable using MOVX
instruction)
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Rev. 1.4