PIC16F946-ESLASHMLQTP datasheet(143/330 Pages) MICROCHIP

143 / 330 page

DS41250F-page 141

PIC16F913/914/916/917/946

9.4

AUSART Operation During Sleep

The AUSART will remain active during Sleep only in the

Synchronous Slave mode. All other modes require the

system clock and therefore cannot generate the neces-

sary signals to run the Transmit or Receive Shift regis-

ters during Sleep.

Synchronous Slave mode uses an externally generated

clock to run the Transmit and Receive Shift registers.

9.4.1

SYNCHRONOUS RECEIVE DURING

SLEEP

To receive during Sleep, all the following conditions

must be met before entering Sleep mode:

• RCSTA and TXSTA Control registers must be

configured for Synchronous Slave Reception (see

Section 9.3.2.4 “Synchronous Slave

Reception Set-up:”).

• If interrupts are desired, set the RCIE bit of the

PIE1 register and the PEIE bit of the INTCON

• The RCIF interrupt flag must be cleared by read-

ing RCREG to unload any pending characters in

the receive buffer.

Upon entering Sleep mode, the device will be ready to

accept data and clocks on the RX/DT and TX/CK pins,

respectively. When the data word has been completely

clocked in by the external device, the RCIF interrupt

flag bit of the PIR1 register will be set. Thereby, waking

the processor from Sleep.

Upon waking from Sleep, the instruction following the

SLEEP

instruction will be executed. If the GIE global

interrupt enable bit of the INTCON register is also set,

then the Interrupt Service Routine at address 004h will

be called.

9.4.2

SYNCHRONOUS TRANSMIT

DURING SLEEP

To transmit during Sleep, all the following conditions

must be met before entering Sleep mode:

• RCSTA and TXSTA Control registers must be

configured for Synchronous Slave Transmission

(see Section 9.3.2.2 “Synchronous Slave

Transmission Set-up:”).

• The TXIF interrupt flag must be cleared by writing

the output data to the TXREG, thereby filling the

TSR and transmit buffer.

• If interrupts are desired, set the TXIE bit of the

PIE1 register and the PEIE bit of the INTCON

Upon entering Sleep mode, the device will be ready to

accept clocks on TX/CK pin and transmit data on the

RX/DT pin. When the data word in the TSR has been

completely clocked out by the external device, the

pending byte in the TXREG will transfer to the TSR and

the TXIF flag will be set. Thereby, waking the processor

from Sleep. At this point, the TXREG is available to

accept another character for transmission, which will

clear the TXIF flag.

Upon waking from Sleep, the instruction following the

SLEEP

instruction will be executed. If the GIE global

interrupt enable bit is also set then the Interrupt Service

Routine at address 0004h will be called.

PIC16F946-E/MLQTP Datasheet(PDF) 143 Page - Microchip Technology

PIC16F946-E/MLQTP Datasheet(HTML) 143 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL