MSP430F551X_1 Datasheet, PDF (25/115 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLER

MSP430F551x
MSP430F552x
www.ti.com
PIN
P4.0/P4MAP0
P4.1/P4MAP1
P4.2/P4MAP2
P4.3/P4MAP3
P4.4/P4MAP4
P4.5/P4MAP5
P4.6/P4MAP6
P4.7/P4MAP7
SLAS590D – OCTOBER 2009 – REVISED APRIL 2010
Table 10. Default Mapping
PxMAPy MNEMONIC
PM_UCB1STE/PM_UCA1CLK
PM_UCB1SIMO/PM_UCB1SDA
PM_UCB1SOMI/PM_UCB1SCL
PM_UCB1CLK/PM_UCA1STE
PM_UCA1TXD/PM_UCA1SIMO
PM_UCA1RXD/PM_UCA1SOMI
PM_NONE
PM_NONE
INPUT PIN FUNCTION
OUTPUT PIN FUNCTION
USCI_B1 SPI slave transmit enable (direction controlled by USCI)
USCI_A1 clock input/output (direction controlled by USCI)
USCI_B1 SPI slave in master out (direction controlled by USCI)
USCI_B1 I2C data (open drain and direction controlled by USCI)
USCI_B1 SPI slave out master in (direction controlled by USCI)
USCI_B1 I2C clock (open drain and direction controlled by USCI)
USCI_A1 SPI slave transmit enable (direction controlled by USCI)
USCI_B1 clock input/output (direction controlled by USCI)
USCI_A1 UART TXD (Direction controlled by USCI - output)
USCI_A1 SPI slave in master out (direction controlled by USCI)
USCI_A1 UART RXD (Direction controlled by USCI - input)
USCI_A1 SPI slave out master in (direction controlled by USCI)
None
DVSS
None
DVSS
Oscillator and System Clock
The clock system in the MSP430F552x and MSP430F551x family of devices is supported by the Unified Clock
System (UCS) module that includes support for a 32 kHz watch crystal oscillator (XT1 LF mode - XT1 HF mode
not supported), an internal very-low-power low-frequency oscillator (VLO), an internal trimmed low-frequency
oscillator (REFO), an integrated internal digitally-controlled oscillator (DCO), and a high-frequency crystal
oscillator XT2. The UCS module is designed to meet the requirements of both low system cost and low-power
consumption. The UCS module features digital frequency locked loop (FLL) hardware that, in conjunction with a
digital modulator, stabilizes the DCO frequency to a programmable multiple of the selected FLL reference
frequency. The internal DCO provides a fast turn-on clock source and stabilizes in less than 5 µs. The UCS
module provides the following clock signals:
• Auxiliary clock (ACLK), sourced from a 32 kHz watch crystal (XT1), a high-frequency crystal (XT2), the
internal low-frequency oscillator (VLO), the trimmed low-frequency oscillator (REFO), or the internal
digitally-controlled oscillator DCO.
• Main clock (MCLK), the system clock used by the CPU. MCLK can be sourced by same sources made
available to ACLK.
• Sub-Main clock (SMCLK), the subsystem clock used by the peripheral modules. SMCLK can be sourced by
same sources made available to ACLK.
• ACLK/n, the buffered output of ACLK, ACLK/2, ACLK/4, ACLK/8, ACLK/16, ACLK/32.
Power Management Module (PMM)
The PMM includes an integrated voltage regulator that supplies the core voltage to the device and contains
programmable output levels to provide for power optimization. The PMM also includes supply voltage supervisor
(SVS) and supply voltage monitoring (SVM) circuitry, as well as brownout protection. The brownout circuit is
implemented to provide the proper internal reset signal to the device during power-on and power-off. The
SVS/SVM circuitry detects if the supply voltage drops below a user-selectable level and supports both supply
voltage supervision (the device is automatically reset) and supply voltage monitoring (SVM, the device is not
automatically reset). SVS and SVM circuitry is available on the primary supply and core supply.
Hardware Multiplier
The multiplication operation is supported by a dedicated peripheral module. The module performs operations with
32-bit, 24-bit, 16-bit, and 8-bit operands. The module is capable of supporting signed and unsigned multiplication
as well as signed and unsigned multiply and accumulate operations.
Real-Time Clock (RTC_A)
The RTC_A module can be used as a general-purpose 32-bit counter (counter mode) or as an integrated
real-time clock (RTC) (calendar mode). In counter mode, the RTC_A also includes two independent 8-bit timers
that can be cascaded to form a 16-bit timer/counter. Both timers can be read and written by software. Calendar
mode integrates an internal calendar which compensates for months with less than 31 days and includes leap
year correction. The RTC_A also supports flexible alarm functions and offset-calibration hardware.
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