ST7PSCR1E4M1/XXX View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST7PSCR1E4M1/XXX

8-BIT LOW-POWER, FULL-SPEED USB MCU WITH 16K FLASH, 768 RAM, SMARTCARD I/F, TIMER

STMicroelectronics 

ST7SCR

SMARTCARD INTERFACE (Cont’d)

SMARTCARD CONTACT CONTROL REGISTER

(CRDCCR)

Read/Write

Reset Value: 00xx xx00 (xxh)

7

CLK -

SEL

CRD CRD CRD CRD

C8 C4 IO CLK

CRD

RST

0

CRD

VCC

Note: To modify the content of this register, the LD

instruction must be used (do not use the BSET

and BRES instructions).

Bit 7 = CLKSEL Card clock selection.

This bit is set and cleared by software.

0: The signal on the CRDCLK pin is a copy of the

CRDCLK bit.

1: The signal on the CRDCLK pin is a 4MHz fre-

quency clock.

Note: To start the clock at a known level, the CRD-

CLK bit should be changed before the CLKSEL

bit.

Bit 3 = CRDIO CRDIO pin control.

This bit is active only if the UART bit in the CRDCR

Register is reset. Reading this bit returns the value

present on the CRDIO pin.

If the UART bit is reset:

– Writing “0” forces a low level on the CRDIO pin

– Writing “1” forces the CRDIO pin to open drain

Hi-Z.

Bit 2 = CRDCLK CRDCLK pin control

This bit is active only if the CLKSEL bit of the CRD-

CCR register is reset. Reading this bit returns the

value present in the register (not the CRDCLK pin

value).

When the CLKSEL bit is reset:

0: Level 0 to be applied on CRDCLK pin.

1: Level 1 to be applied on CRDCLK pin.

Note: To ensure that the clock stops at a given

value, write the desired value in the CRDCLK bit

prior to changing the CLKSEL bit from 1 to 0.

Bit 6 = Reserved, must be kept cleared.

Bit 5 = CRDC8 CRDC8 pin control.

Reading this bit returns the value present on the

CRDC8 pin. Writing this bit outputs the bit value on

the pin.

Bit 4 = CRDC4 CRDC4 pin control

Reading this bit returns the value present on the

CRDC4 pin. Writing this bit outputs the bit value on

the pin.

Figure 37. Smartcard I/O Pin Structure

Bit 1 = CRDRST CRDRST pin control.

Reading this bit returns the value present on the

CRDRST pin. Writing this bit outputs the bit value

on the pin.

Bit 0 = CRDVCC CRDVCC Pin Control.

This bit is set and cleared by software and forced

to 0 by hardware when no card is present

(CRDIRF bit=0).

0: No voltage to be applied on the CRDVCC pin.

1: The selected voltage must be applied on the

CRDVCC pin.

I/O PIN

CRDCCR

REGISTER

DATA BUS

64/102

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