AT89C5122D-RDRUM Atmel, AT89C5122D-RDRUM Datasheet - Page 48

• Manufacturer Part Number: AT89C5122D-RDRUM
• Description: IC 8051 MCU 32K CRAM USB 64-VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C5122D-RDRUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: SmartCard, SPI, UART/USART, USB
• Peripherals: LED, POR, WDT
• Number Of I /o: 46
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCUAT89STK-10 - KIT EVAL APPL MASS STORAGEAT89STK-03 - KIT STARTER FOR MCU AT8XC5122/23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Other names: AT89C5122D-RDRUMTR

USB Interface Clock
Registers
48
AT83R5122, AT8xC5122/23
The USB Interface uses two clocks :
Table 24. Clock Selection Register - CKSEL (S:85h)
Reset Value = XXXX XXX0b
Table 25. Clock Reload Register - CKRL (S:97h)
Reset Value = XXXX 1111b
Bit Number Bit Mnemonic Description
Bit Number Bit Mnemonic Description
–
–
7 - 4
7
7:1
7
3:0
-
-
0
The first one is the CPU clock used for the interface with the microcontroller,
CK_IDLE.
The second one is the CK_USB supplied from the PLL through a divider by
2.
CKRL3:0
6
6
-
-
CKS
-
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
CPU Oscillator Select Bit
Set this bit to connect CPU and Peripherals to PLL output.
Clear this to to connect CPU and Peripherals to XTAL1 clock input.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Clock Reload register
Prescaler1 value
F
ck_cpu
5
5
-
-
=[ 1 / 2*(16-CKRL)] * F
4
4
-
-
CKRL3
3
3
-
ck_XTAL1
CKRL2
2
2
-
CKRL1
1
1
-
4202F–SCR–07/2008
CKRL0
CKS
0
0