ST92163R4D1L View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST92163R4D1L

8/16-BIT FULL SPEED USB MCU FOR COMPOSITE DEVICES WITH 16 ENDPOINTS, 20K ROM, 2K RAM, I2C, SCI, & MFT

STMicroelectronics 

ST92163 - RESET AND CLOCK CONTROL UNIT (RCCU)

5.3 CLOCK MANAGEMENT

The various programmable features and operating modes of the CCU are handled by four registers:

– MODER (Mode Register)

This is a System Register (R235, Group E).

– CLK_FLAG (Clock Flag Register)

This is a Paged Register (R242, Page 55).

The input clock divide-by-two and the CPU clock

prescaler factors are handled by this register.

This register contains various status flags, as

well as control bits for clock selection.

– CLKCTL (Clock Control Register)

This is a Paged Register (R240, Page 55).

The low power modes and the interpretation of

the HALT instruction are handled by this register.

– PLLCONF (PLL Configuration Register)

This is a Paged Register (R246, Page 55).

The PLL multiplication and division factors are

programmed in this register.

Figure 36. Clock Control Unit Programming

XTSTO P

(CLK_FLAG)

DIV2

(MODER)

CSU_CKSEL

(CLK_FLAG)

CKAF_SEL

(CLKCTL)

1/16

0

PLL

0

Quartz

oscillator

x

1/2 1 CLOCK2 6/8/10/14

1/N

1

CLOCK1

Internal

RC

oscillator

1/16

OUTPLL_2

0

(USB CLOCK)

1 CK_AF

WFI and LPOWFI=1 and WFI_CKSEL = 1

MX(1:0) DX(2:0)

(PLLCONF)

0

0

INTCLK

1

1

to

Peripherals

and

CPU Clock Prescaler

XT_DIV16 CKAF_ST

(CLK_FLAG)

Wait for Interrupt and Low Power Modes:

LPOWFI (CLKCTL) selects Low Power operation automatically on entering WFI mode.

WFI_CKSEL (CLKCTL) selects the CK_AF clock automatically, if present, on entering WFI mode.

XTSTOP (CLK_FLAG) automatically stops the Xtal oscillator when the CK_AF clock is present and selected.

77/224

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