SZF2002 データシートの表示（PDF） - Philips Electronics

部品番号

コンポーネント説明

メーカー

SZF2002

Low voltage 8-bit microcontroller with 6-kbyte embedded RAM

Philips Electronics 

Philips Semiconductors

Low voltage 8-bit microcontroller with

6-kbyte embedded RAM

Product specification

SZF2002

9 MEMORY ORGANIZATION

The SZF2002 has 6 kbytes of program memory plus

6 kbytes + 256 bytes of data memory on chip. The device

has separate address spaces for program and data

memory (see Fig.4).

The SZF2002 can directly address up to 256 kbytes of

external data memory. The CPU generates the read

strobe (OE), the write strobe (WE) and chip select (CE) for

external program memory (Flash), and read strobe (OE)

and write strobe (WE) and chip select (RAMCE) for

external data memory.

9.1 Program memory

The SZF2002 contains 6 kbytes of internal ROM and

6144 + 256 bytes of RAM. The lower 6 kbytes of program

memory can be implemented in either on-chip ROM or

external program memory. The 6 kbytes of program

memory is implemented as mask programmable ROM.

There are two modes for the program memory, depending

on the state of the EA pin (latched during reset) and on the

address range:

1. EA = 0. All program fetches are directed to the

external program memory. After reset the CPU begins

execution at location 8000H.

2. EA = 1. After reset the CPU begins execution at

location 0000H. Fetches from addresses

2000H to 37FFH are redirected to the Auxiliary RAM.

The processor can fill this RAM with normal write

operations to the data memory (MOVX to addresses

0000H to 17FFH). Program memory fetches from

addresses 0000H to 17FFH are directed to the

internal ROM.

Program Counter values greater than 7FFFH are

automatically addressed to external memory regardless of

the state of the EA pin.

9.2 Data memory

The SZF2002 contains 6144 + 256 bytes of RAM and a

number of Special Function Registers (SFRs). All these

data spaces are addressed differently. Figure 4 shows the

internal data memory space divided into the lower

128 bytes, the upper 128 bytes, Auxiliary RAM, and the

SFRs space. Internal RAM locations 0 to 127 are directly

and indirectly addressed. Internal RAM locations

128 to 255 are only indirectly addressed.

The Special Function Register locations 128 to 255 are

only directly addressed. Auxiliary RAM is accessible via

MOVX instructions to the lower 32-kbyte address space.

MOVX @R0/R1 instructions use SFR P2 as page

selector. The upper 32-kbyte address space is redirected

to the program memory, to accommodate flash

programming.

9.3 Special Function Registers (SFRs)

The upper 128 bytes are the address locations of the

SFRs. Figures 6 and 7 show the Special Function

Registers space. The SFRs include the port latches,

timers, peripheral control, serial I/O registers, etc. These

registers are accessed by direct addressing. There are

128 directly addressed locations in the SFR address

space. Bit addressed SFRs are those that end in 000B.

9.4 Addressing

The SZF2002 has five methods for addressing source

operands:

• Register

• Direct

• Indirect

• Immediate

• Base-Register plus Index-Register-Indirect.

The first three methods can be used for addressing

destination operands. Most instructions have a

‘destination/source’ field that specifies the data type,

addressing methods and operands involved.

For operations other than MOVs, the destination operand

is also a source operand.

Access to memory addressing is as follows:

• Registers in one of the four register banks through Direct

or Indirect (see Fig.5)

• Lower 128 bytes of internal RAM through Direct or

register Indirect; upper 128 bytes of internal RAM

through Indirect

• Special Function Registers through Direct

• Program memory look-up tables through Base-Register

plus Index-Register-Indirect

• Extended data memory access through register Indirect.

1998 Aug 26

11

Share Link: