C8051F310 参数 Datasheet PDF下载

C8051F310/1/2/3/4/5/6/7

10.1.3. Flash Write Procedure

Flash bytes are programmed by software with the following sequence:

Step 1. Disable interrupts (recommended).

Step 2. Erase the 512-byte Flash page containing the target location, as described in

Step 3. Set the PSWE bit (register PSCTL).

Step 4. Clear the PSEE bit (register PSCTL).

Step 5. Write the first key code to FLKEY: 0xA5.

Step 6. Write the second key code to FLKEY: 0xF1.

Step 7. Using the MOVX instruction, write a single data byte to the desired location within the

512 byte sector.

Steps 5–7 must be repeated for each byte to be written. After Flash writes are complete, PSWE should be

cleared so that MOVX instructions do not target program memory.

Table 10.1. Flash Electrical Characteristics

V

DD

= 2.7 to 3.6 V; –40 to +85 °C unless otherwise specified.

Parameter

Conditions

Min

C8051F310/1/6/7

16384*

Flash Size

C8051F312/3/4/5

8192

Endurance

20 k

Erase Cycle Time

25 MHz System Clock

10

Write Cycle Time

25 MHz System Clock

40

*Note:

512 bytes at locations 0x3E00 (C8051F310/1) are reserved.

Typ

—

—

100 k

15

55

Max

—

—

—

20

70

Units

bytes

Erase/Write

ms

µs

10.2. Non-volatile Data Storage

The Flash memory can be used for non-volatile data storage as well as program code. This allows data

such as calibration coefficients to be calculated and stored at run time. Data is written using the MOVX

write instruction and read using the MOVC instruction. Note: MOVX read instructions always target XRAM.

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Rev. 1.7