ST62P32BQ3 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST62P32BQ3

8-BIT OTP/EPROM MCUs WITH A/D CONVERTER, 16-BIT AUTO-RELOAD TIMER, EEPROM, SPI AND UART

STMicroelectronics 

ST62T32B ST62E32B

CONTROL REGISTERS (Cont’d)

Status Control Register 4 (SCR4)

Address: E3h - Read/Write/Clear only

7

0

Res.

Res.

Res.

Res.

OVFPO

L

OVFEN

PMPOL

PWME

N

Bit7- Bit4 = Reserved, set to 0.

Bit 3 = OVFPOL. Overflow Output Polarity. This bit

defines the polarity for the Overflow Output OVF.

When 0, OVF is set on every overflow event if en-

abled in Set mode (OVFEN = 1, OVFMD = 0). The

reset state of OVF is 0.

When 1, OVF is reset on every overflow event if

enabled in Set mode.

The reset state of OVF is 1.

Bit 2 = OVFEN. Overflow Output Enable. This bit

enables the Overflow output OVF. When 0 the

Overflow output is disabled: if OVFPOL = 0, the

state of OVF is 0, if OVFPOL = 1, the state of

OVF = 1.The Overflow Output is enabled when

this bit = 1, it must be set to use the OVF output.

Bit 1 = PWMPOL. PWM Output Polarity. This bit

defines the polarity for the PWM Output PWM.

When 0, PWM is set on every Masked-Counter

Zero event and is reset on a Masked-Compare if

enabled in Set/Reset mode (PWMEN = 1, PWM-

MD = 0).

The reset state of PWM pin is 0 When 1, OVF is

set on every Masked-Compare event and is reset

on a Masked-Counter Zero event if enabled in

Set/Reset mode (PWMEN = 1, PWMMD = 0).

The reset state of PWM is 1.

Bit 0 = PWMEN. PWM Output Enable. This bit en-

ables the PWM output PWM. When 0 the PWM

output is disabled: if PWMPOL = 0, the state of

PWM is 0, if PWMPOL = 1, the state of PWM = 1.

The PWM Output is enabled when this bit = 1, it

must be set to use the PWM output.

Notes:

A Masked-Compare is the logical AND of the Mask

Register MASK with the Counter Register CT,

compared with the logical AND of the compare

Register CMP: [(MASK & CT) = (MASK&CMP)].

A Masked-Counter Zero is the logical AND of the

Mask Register MASK with the Counter Register

CT, compared with zero: [(MASK & CT) = 0000h].

4.3.6 16-BIT REGISTERS

Note: Care must be taken when using single-bit

instructions (RES/SET/INC/DEC) 16-bit registers

(RLCP, CP, CMP, MSK) since these instructions

imply a READ-MODIFY-WRITE operation on the

register. As the ST6 is based on a 8-bit architec-

ture, to write a 16-bit register, the high byte must

be written first to an intermediate register (latch

register) and the whole 16-bit register is loaded at

the same time as the low byte is written. A WRITE

operation of the HIGH byte is performed on the in-

termediate register (latch register) but a READ op-

eration of the HIGH byte is directly performed on

the 16-bit register (last loaded value). As a conse-

quence, it is always mandatory to write the LOW

byte before any single-bit instruction on the HIGH

byte in order to load the value set in the intermedi-

ate register to the 16-bit register (refresh the 16-bit

register).

Example:

The following sequence is NOT GOOD:

ldi t16cmph, 055h

ldi t16cmpl, 000h

; t16cmp (16-bit register )=5500h

ldi t16cmph, 0AAh

; t16cmp (16-bit register )=5500h

inc t16cmph

; t16cmp (16-bit register )=5500h

ldi t16cmpl, 000h

; t16cmp (16-bit register )=5600h

; and NOT AB00h

The CORRECT sequence is:

ldi t16cmph, 055h

ldi t16cmpl, 000h

; t16cmp (16-bit register )=5500h

ldi t16cmph, 0AAh

; t16cmp (16-bit register )=5500h

ldi t16cmpl, 000h

; t16cmp (16-bit register )=AA00h

inc t16cmph

; t16cmp (16-bit register )=AA00h

ldi t16cmpl, 000h

;t16cmp (16-bit register )=AB00h

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