C8051F343-GQ Silicon Laboratories Inc, C8051F343-GQ Datasheet - Page 99

• Manufacturer Part Number: C8051F343-GQ
• Description: IC 8051 MCU FLASH 32K 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F34xr

Specifications of C8051F343-GQ

• Program Memory Type: FLASH
• Program Memory Size: 32KB (32K x 8)
• Package / Case: 32-LQFP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 25
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 21x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F3x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 2304 B
• Interface Type: I2C, SMBus, SPI, UART, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 4
• Operating Supply Voltage: 2.7 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: KSK-SL-F34X, KSK-SL-TOOLSTICK, PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F340DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 17 Channel
• Package: 32LQFP
• Device Core: 8051
• Family Name: C8051F34x
• Maximum Speed: 48 MHz
• Data Rom Size: 128 B
• A/d Bit Size: 10 bit
• A/d Channels Available: 17
• Height: 1.4 mm
• Length: 7 mm
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Width: 7 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1748 - ADAPTER TOOLSTICK FOR C8051F34X770-1006 - ISP 4PORT FOR SILABS C8051F MCU
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1301

10. Prefetch Engine
The 48 MHz versions of the C8051F34x family of devices incorporate a 2-byte prefetch engine. Because
the access time of the FLASH memory is 40 ns, and the minimum instruction time is roughly 20 ns, the
prefetch engine is necessary for full-speed code execution. Instructions are read from FLASH memory two
bytes at a time by the prefetch engine, and given to the CIP-51 processor core to execute. When running
linear code (code without any jumps or branches), the prefetch engine allows instructions to be executed
at full speed. When a code branch occurs, the processor may be stalled for up to two clock cycles while the
next set of code bytes is retrieved from FLASH memory. The FLRT bit (FLSCL.4) determines how many
clock cycles are used to read each set of two code bytes from FLASH. When operating from a system
clock of 25 MHz or less, the FLRT bit should be set to ‘0’ so that the prefetch engine takes only one clock
cycle for each read. When operating with a system clock of greater than 25 MHz (up to 48 MHz), the FLRT
bit should be set to ‘1’, so that each prefetch code read lasts for two clock cycles.
Bits 7–6: Unused. Read = 00b; Write = Don’t Care
Bit 5:
Bits 4–1: Unused. Read = 0000b; Write = Don’t Care
Bit 0:
Bit7
R
PFEN: Prefetch Enable.
This bit enables the prefetch engine.
0: Prefetch engine is disabled.
1: Prefetch engine is enabled.
FLBWE: FLASH Block Write Enable.
This bit allows block writes to FLASH memory from software.
0: Each byte of a software FLASH write is written individually.
1: FLASH bytes are written in groups of two.
Bit6
SFR Definition 10.1. PFE0CN: Prefetch Engine Control
R
PFEN
R/W
Bit5
C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D
Bit4
R
Rev. 1.3
Bit3
R
Bit2
R
Bit1
R
SFR Address: 0xAF
FLBWE
R/W
Bit0
00100000
Reset Value
99