PIC18F24J11 MICROCHIP [Microchip Technology], PIC18F24J11 Datasheet - Page 280

• Manufacturer Part Number: PIC18F24J11
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F46J11 FAMILY
19.3.9
In SPI Master mode, module clocks may be operating
at a different speed than when in full-power mode. In
the case of Sleep mode, all clocks are halted.
In Idle modes, a clock is provided to the peripherals.
That clock can be from the primary clock source, the
secondary clock (Timer1 oscillator) or the INTOSC
source. See
Oscillator Switching”
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
If MSSP interrupts are enabled, they can wake the
controller from Sleep mode, or one of the Idle modes,
when the master completes sending data. If an exit
from Sleep or Idle mode is not desired, MSSP
interrupts should be disabled.
If the Sleep mode is selected, all module clocks are
halted and the transmission/reception will remain in
that state until the device wakes. After the device
returns to Run mode, the module will resume
transmitting and receiving data.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any power-managed
mode
Transmit/Receive Shift register. When all 8 bits have
been received, the MSSP interrupt flag bit will be set,
and if enabled, will wake the device.
19.3.10
A Reset disables the MSSP module and terminates the
current transfer.
DS39932D-page 280
and
OPERATION IN POWER-MANAGED
MODES
EFFECTS OF A RESET
data
Section 3.3 “Clock Sources and
to be
for additional information.
shifted into
the
SPI
19.3.11
Table 19-1
standard SPI modes and the states of the CKP and
CKE control bits.
TABLE 19-1:
There is also an SMP bit, which controls when the data
is sampled.
19.3.12
Because MSSP1 and MSSP2 are independent
modules, they can operate simultaneously at different
data rates. Setting the SSPM<3:0> bits of the
SSPxCON1 register determines the rate for the
corresponding module.
An exception is when both modules use Timer2 as a
time base in Master mode. In this instance, any
changes to the Timer2 module’s operation will affect
both MSSP modules equally. If different bit rates are
required for each module, the user should select one of
the other three time base options for one of the
modules.
Standard SPI Mode
Terminology
0, 0
0, 1
1, 0
1, 1
BUS MODE COMPATIBILITY
SPI CLOCK SPEED AND MODULE
INTERACTIONS
provides the compatibility between the
SPI BUS MODES
 2011 Microchip Technology Inc.
CKP
Control Bits State
0
0
1
1
CKE
1
0
1
0