ST7PLITEU09M3TR View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST7PLITEU09M3TR

8-bit MCU with single voltage Flash memory, ADC, timers

STMicroelectronics 

ST7LITEU05 ST7LITEU09

7.2 REGISTER DESCRIPTION

MAIN CLOCK CONTROL/STATUS REGISTER

(MCCSR)

Read / Write

Reset Value: 0000 0000 (00h)

7

0

0

0

0

0

0

0 MCO SMS

Bits 7:2 = Reserved, must be kept cleared.

Bit 1 = MCO Main Clock Out enable

This bit is read/write by software and cleared by

hardware after a reset. This bit allows to enable

the MCO output clock.

0: MCO clock disabled, I/O port free for general

purpose I/O.

1: MCO clock enabled.

Bit 0 = SMS Slow Mode select

This bit is read/write by software and cleared by

hardware after a reset. This bit selects the input

clock fOSC or fOSC/32.

0: Normal mode (fCPU = fOSC

1: Slow mode (fCPU = fOSC/32)

RC CONTROL REGISTER (RCCR)

Read / Write

Reset Value: 1111 1111 (FFh)

7

0

CR9 CR8 CR7 CR6 CR5 CR4 CR3 CR2

Note: To tune the oscillator, write a series of differ-

ent values in the register until the correct frequen-

cy is reached. The fastest method is to use a di-

chotomy starting with 80h.

SYSTEM INTEGRITY (SI) CONTROL/STATUS

REGISTER (SICSR)

Read / Write

Reset Value: 0000 0x00 (0xh)

7

0

0 CR1 CR0 0 0 LVDRF AVDF AVDIE

Bit 7 = Reserved, must be kept cleared.

Bits 6:5 = CR[1:0] RC Oscillator Frequency Ad-

justment bits

These bits, as well as CR[9:2] bits in the RCCR

register must be written immediately after reset to

adjust the RC oscillator frequency and to obtain

the required accuracy. Refer to section 7.1 on

page 22.

Bits 4:3 = Reserved, must be kept cleared.

Bits 2:0 = System Integrity bits. Refer to Section

8.4 SYSTEM INTEGRITY MANAGEMENT (SI).

Bits 7:0 = CR[9:2] RC Oscillator Frequency Ad-

justment Bits

These bits, as well as CR[1:0] bits in the SICSR

register must be written immediately after reset to

adjust the RC oscillator frequency and to obtain

the required accuracy. The application can store

the correct value for each voltage range in Flash

memory and write it to this register at start-up.

00h = maximum available frequency

FFh = lowest available frequency

24/115

1

Share Link: