C8051F321 Silicon Laboratories Inc, C8051F321 Datasheet - Page 146

• Manufacturer Part Number: C8051F321
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F321

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

C8051F320/1
15.3. USB Register Access
The USB0 controller registers listed in Table 15.2 are accessed through two SFRs: USB0 Address (USB0ADR) and
USB0 Data (USB0DAT). The USB0ADR register selects which USB register is targeted by reads/writes of the
USB0DAT register. See Figure 15.3.
Endpoint control/status registers are accessed by first writing the USB register INDEX with the target endpoint num-
ber. Once the target endpoint number is written to the INDEX register, the control/status registers associated with the
target endpoint may be accessed. See the “Indexed Registers” section of Table 15.2 for a list of endpoint control/sta-
tus registers.
Important Note: The USB clock must be active when accessing USB registers.
146
USB0ADR
USB0DAT
SFRs
8051
Figure 15.3. USB0 Register Access Scheme
Rev. 1.1
Registers
Registers
Common
Interrupt
Register
Access
Index
FIFO
USB Controller
Endpoint0 Control/
Endpoint1 Control/
Endpoint2 Control/
Endpoint3 Control/
Status Registers
Status Registers
Status Registers
Status Registers