Data Sheet

LPC2921/2923/2925
ARM9 microcontroller with CAN, LIN, and USB
Rev. 03 — 14 April 2010
Product data sheet
1. General description
The LPC2921/2923/2925 combine an ARM968E-S CPU core with two integrated TCM
blocks operating at frequencies of up to 125 MHz, Full-speed USB 2.0 device controller,
CAN and LIN, up to 40 kB SRAM, up to 512 kB flash memory, two 10-bit ADCs, and
multiple serial and parallel interfaces in a single chip targeted at consumer, industrial, and
communication markets. To optimize system power consumption, the
LPC2921/2923/2925 has a very flexible Clock Generation Unit (CGU) that provides
dynamic clock gating and scaling.
2. Features and benefits
„ ARM968E-S processor running at frequencies of up to 125 MHz maximum.
„ Multilayer AHB system bus at 125 MHz with four separate layers.
„ On-chip memory:
‹ Two Tightly Coupled Memories (TCM), 16 kB Instruction (ITCM) and 16 kB Data
TCM (DTCM).
‹ On the LPC2925, two separate internal Static RAM (SRAM) instances, 16 kB each.
‹ On the LPC2923 and LPC2921, one 16 kB SRAM block.
‹ 8 kB ETB SRAM, also usable for code execution and data.
‹ Up to 512 kB high-speed flash-program memory.
‹ 16 kB true EEPROM, byte-erasable/programmable.
„ Dual-master, eight-channel GPDMA controller on the AHB multilayer matrix which can
be used with the Serial Peripheral Interface (SPI) interfaces and the UARTs, as well as
for memory-to-memory transfers including the TCM memories.
„ Serial interfaces:
‹ USB 2.0 full-speed device controller with dedicated DMA controller and on-chip
device PHY.
‹ Two-channel CAN controller supporting FullCAN and extensive message filtering.
‹ Two LIN master controllers with full hardware support for LIN communication. The
LIN interface can be configured as UART to provide two additional UART
interfaces.
‹ Two 550 UARTs with 16-byte Tx and Rx FIFO depths, DMA support, and
RS-485/EIA-485 (9-bit) support.
‹ Three full-duplex Q-SPIs with four slave-select lines; 16 bits wide; 8 locations deep;
Tx FIFO and Rx FIFO.
‹ Two I2C-bus interfaces.
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
„ Other peripherals:
‹ Two 10-bit ADCs, 8-channels each, with 3.3 V measurement range provide 8
analog inputs each with conversion times as low as 2.44 μs per channel. Each
channel provides a compare function to minimize interrupts.
‹ Multiple trigger-start option for all ADCs: timer, PWM, other ADC and external
signal input.
‹ Four 32-bit timers each containing four capture-and-compare registers linked to
I/Os.
‹ Four six-channel PWMs (Pulse Width Modulators) with capture and trap
functionality.
‹ Two dedicated 32-bit timers to schedule and synchronize PWM and ADC.
‹ Quadrature encoder interface that can monitor one external quadrature encoder.
‹ 32-bit watchdog with timer change protection, running on safe clock.
„ Up to 60 general-purpose I/O pins with programmable pull-up, pull-down, or bus
keeper.
„ Vectored Interrupt Controller (VIC) with 16 priority levels.
„ Up to 16 level-sensitive external interrupt pins, including USB, CAN and LIN wake-up
features.
„ Configurable clock out pin for driving external system clocks.
„ Processor wake-up from power-down via external interrupt pins and CAN or LIN
activity.
„ Flexible Reset Generator Unit (RGU) able to control resets of individual modules.
„ Flexible Clock-Generation Unit (CGU) able to control clock frequency of individual
modules:
‹ On-chip very low-power ring oscillator; fixed frequency of 0.4 MHz; always on to
provide a Safe_Clock source for system monitoring.
‹ On-chip crystal oscillator with a recommended operating range from 10 MHz to
25 MHz. PLL input range 10 MHz to 25 MHz.
‹ On-chip PLL allows CPU operation up to a maximum CPU rate of 125 MHz.
‹ Generation of up to 11 base clocks.
‹ Seven fractional dividers.
„ Second, dedicated CGU with its own PLL generates the USB clock and a configurable
clock output.
„ Highly configurable system Power Management Unit (PMU):
‹ clock control of individual modules.
‹ allows minimization of system operating power consumption in any configuration.
„ Standard ARM test and debug interface with real-time in-circuit emulator.
„ Boundary-scan test supported.
„ ETM/ETB debug functions with 8 kB of dedicated SRAM also accessible for
application code and data storage.
„ Dual power supply:
‹ CPU operating voltage: 1.8 V ± 5 %.
‹ I/O operating voltage: 2.7 V to 3.6 V; inputs tolerant up to 5.5 V.
„ 100-pin LQFP package.
„ −40 °C to +85 °C ambient operating temperature range.
LPC2921_23_25_3
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 03 — 14 April 2010
© NXP B.V. 2010. All rights reserved.
2 of 84
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
3. Ordering information
Table 1.
Ordering information
Type number
Package
Name
Description
Version
LPC2921FBD100 LQFP100
plastic low profile quad flat package; 100 leads; body 14 × 14 × 1.4 mm
SOT407-1
LPC2923FBD100 LQFP100
plastic low profile quad flat package; 100 leads; body 14 × 14 × 1.4 mm
SOT407-1
LPC2925FBD100 LQFP100
plastic low profile quad flat package; 100 leads; body 14 × 14 × 1.4 mm
SOT407-1
3.1 Ordering options
Table 2.
LPC2921_23_25_3
Product data sheet
Part options
Type number
Flash
SRAM (incl. USB
UART
LIN 2.0/
memory ETB SRAM) device RS-485 UART
CAN
Package
LPC2921FBD100
128 kB
24 kB
yes
2
2
2
LQFP100
LPC2923FBD100
256 kB
24 kB
yes
2
2
2
LQFP100
LPC2925FBD100
512 kB
40 kB
yes
2
2
2
LQFP100
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Rev. 03 — 14 April 2010
© NXP B.V. 2010. All rights reserved.
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ARM9 microcontroller with CAN, LIN, and USB
4. Block diagram
JTAG
interface
TEST/DEBUG
INTERFACE
LPC2921/2923/2925
ITCM
16 kB
8 kB SRAM
DTCM
16 kB
ARM968E-S
1 master
2 slaves
master
master
VECTORED
INTERRUPT
CONTROLLER
CLOCK
GENERATION
UNIT
RESET
GENERATION
UNIT
slave
PWM0/1/2/3
slave
AHB TO DTL
BRIDGE
GPDMA REGISTERS
master
slave
AHB TO DTL
BRIDGE
USB DEVICE
CONTROLLER
slave
slave
power, clock, and
reset subsystem
EMBEDDED SRAM 16 kB
slave
EMBEDDED SRAM 16 kB
(LPC2925 only)
POWER
MANAGEMENT
UNIT
TIMER0/1 MTMR
GPDMA CONTROLLER
AHB TO APB
BRIDGE
slave
AHB
MULTILAYER
MATRIX
slave
EMBEDDED FLASH
512/256/128 kB
slave
MSC subsystem
AHB TO APB
BRIDGE
general subsystem
3.3 V ADC1/2
16 kB
EEPROM
SYSTEM CONTROL
EVENT ROUTER
CHIP FEATURE ID
QUADRATURE
ENCODER
slave
AHB TO APB
BRIDGE
slave
CAN0/1
AHB TO APB
BRIDGE
peripheral subsystem
GENERAL PURPOSE I/O
PORTS 0/1/5
TIMER 0/1/2/3
GLOBAL
ACCEPTANCE
FILTER
networking subsystem
RS-485 UART0/1
SPI0/1/2
UART/LIN0/1
WDT
I2C0/1
002aae224
Grey-shaded blocks represent peripherals and memory regions accessible by the GPDMA.
Fig 1.
LPC2921/2923/2925 block diagram
LPC2921_23_25_3
Product data sheet
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Rev. 03 — 14 April 2010
© NXP B.V. 2010. All rights reserved.
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LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
5. Pinning information
76
100
5.1 Pinning
1
75
LPC2921FBD100
LPC2923FBD100
LPC2925FBD100
Fig 2.
50
51
26
25
002aae242
Pin configuration for SOT407-1 (LQFP100)
5.2 Pin description
5.2.1 General description
The LPC2921/2923/2925 uses three ports: port 1 with 32 pins, port 1 with 28 pins, and
port 5 with 2 pins. Ports 4/3/2 are not used. The pin to which each function is assigned is
controlled by the SFSP registers in the SCU. The functions combined on each port pin are
shown in the pin description tables in this section.
5.2.2 LQFP100 pin assignment
Table 3.
LQFP100 pin assignment
Pin name
Pin
Description
TDO
1[1]
IEEE 1149.1 test data out
P0[24]/TXD1/
TXDC1/SCS2[0]
2[1]
GPIO0, pin 24
P0[25]/RXD1/
RXDC1/SDO2
3[1]
P0[26]/TXD1/SDI2
Function 0 (default)
Function 1
Function 2
Function 3
UART1 TXD
CAN1 TXD
SPI2 SCS0
GPIO0, pin 25
UART1 RXD
CAN1 RXD
SPI2 SDO
4[1]
GPIO0, pin 26
-
UART1 TXD
SPI2 SDI
P0[27]/RXD1/SCK2
5[1]
GPIO0, pin 27
-
UART1 RXD
SPI2 SCK
P0[28]/CAP0[0]/
MAT0[0]
6[1]
GPIO0, pin 28
-
TIMER0 CAP0
TIMER0 MAT0
P0[29]/CAP0[1]/
MAT0[1]
7[1]
GPIO0, pin 29
-
TIMER0 CAP1
TIMER0 MAT1
VDD(IO)
8
3.3 V power supply for I/O
P0[30]/CAP0[2]/
MAT0[2]
9[1]
GPIO0, pin 30
-
TIMER0 CAP2
TIMER0 MAT2
P0[31]/CAP0[3]/
MAT0[3]
10[1]
GPIO0, pin 31
-
TIMER0 CAP3
TIMER0 MAT3
VSS(IO)
11
ground for I/O
LPC2921_23_25_3
Product data sheet
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Rev. 03 — 14 April 2010
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5 of 84
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
Table 3.
LQFP100 pin assignment …continued
Pin name
Pin
Description
Function 0 (default)
Function 1
Function 2
Function 3
P5[19]/USB_D+
12[2]
GPIO5, pin 19
USB_D+
-
-
P5[18]/USB_D−
13[2]
GPIO5, pin 18
USB_D−
-
-
VDD(IO)
14
3.3 V power supply for I/O
VDD(CORE)
15
1.8 V power supply for digital core
VSS(CORE)
16
ground for core
VSS(IO)
17
ground for I/O
P1[27]/CAP1[2]/
TRAP2/PMAT3[3]
18[1]
GPIO1, pin 27
TIMER1 CAP2,
ADC2 EXT START
PWM TRAP2
PWM3 MAT3
P1[26]/PMAT2[0]/
TRAP3/PMAT3[2]
19[1]
GPIO1, pin 26
PWM2 MAT0
PWM TRAP3
PWM3 MAT2
VDD(IO)
20
3.3 V power supply for I/O
P1[25]/PMAT1[0]/
USB_VBUS/
PMAT3[1]
21[1]
GPIO1, pin 25
PWM1 MAT0
USB_VBUS
PWM3 MAT1
P1[24]/PMAT0[0]/
USB_CONNECT/
PMAT3[0]
22[1]
GPIO1, pin 24
PWM0 MAT0
USB_CONNECT
PWM3 MAT0
P1[23]/RXD0
23[1]
GPIO1, pin 23
UART0 RXD
-
-
P1[22]/TXD0/
USB_UP_LED
24[1]
GPIO1, pin 22
UART0 TXD
USB_UP_LED
-
TMS
25[1]
IEEE 1149.1 test mode select, pulled up internally
TCK
26[1]
IEEE 1149.1 test clock
P1[21]/CAP3[3]/
CAP1[3]
27[1]
GPIO1, pin 21
TIMER3 CAP3
TIMER1 CAP3,
MSCSS PAUSE
-
P1[20]/CAP3[2]/
SCS0[1]
28[1]
GPIO1, pin 20
TIMER3 CAP2
SPI0 SCS1
-
P1[19]/CAP3[1]/
SCS0[2]
29[1]
GPIO1, pin 19
TIMER3 CAP1
SPI0 SCS2
-
P1[18]/CAP3[0]/
SDO0
30[1]
GPIO1, pin 18
TIMER3 CAP0
SPI0 SDO
-
P1[17]/CAP2[3]/
SDI0
31[1]
GPIO1, pin 17
TIMER2 CAP3
SPI0 SDI
-
VSS(IO)
32
ground for I/O
P1[16]/CAP2[2]/
SCK0
33[1]
GPIO1, pin 16
TIMER2 CAP2
SPI0 SCK
-
P1[15]/CAP2[1]/
SCS0[0]
34[1]
GPIO1, pin 15
TIMER2 CAP1
SPI0 SCS0
-
P1[14]/CAP2[0]/
SCS0[3]
35[1]
GPIO1, pin 14
TIMER2 CAP0
SPI0 SCS3
-
P1[13]/EI3/SCL1
36[1]
GPIO1, pin 13
EXTINT3
I2C1 SCL
-
P1[12]/EI2/SDA1
37[1]
EXTINT2
I2C1
SDA
-
I2C0 SCL
-
GPIO1, pin 12
VDD(IO)
38
3.3 V power supply for I/O
P1[11]/SCK1/SCL0
39[1]
GPIO1, pin 11
LPC2921_23_25_3
Product data sheet
SPI1 SCK
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LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
Table 3.
LQFP100 pin assignment …continued
Pin name
Pin
Description
P1[10]/SDI1/SDA0
40[1]
GPIO1, pin 10
VSS(CORE)
41
ground for digital core
VDD(CORE)
42
1.8 V power supply for digital core
P1[9]/SDO1
43[1]
GPIO1, pin 9
VSS(IO)
44
ground for I/O
P1[8]/SCS1[0]/
TXDL1/CS0
45[1]
P1[7]/SCS1[3]/RXD1
Function 0 (default)
Function 1
Function 2
Function 3
SPI1 SDI
I2C0
-
SDA
SPI1 SDO
-
-
GPIO1, pin 8
SPI1 SCS0
-
-
46[1]
GPIO1, pin 7
SPI1 SCS3
UART1 RXD
-
P1[6]/SCS1[2]/TXD1
47[1]
GPIO1, pin 6
SPI1 SCS2
UART1 TXD
-
P1[5]/SCS1[1]/
PMAT3[5]
48[1]
GPIO1, pin 5
SPI1 SCS1
PWM3 MAT5
-
P1[4]/SCS2[2]/
PMAT3[4]
49[1]
GPIO1, pin 4
SPI2 SCS2
PWM3 MAT4
-
TRST
50[1]
IEEE 1149.1 test reset NOT; active LOW; pulled up internally
RST
51[1]
asynchronous device reset; active LOW; pulled up internally
VSS(OSC)
52
ground for oscillator
XOUT_OSC
53[3]
crystal out for oscillator
XIN_OSC
54[3]
crystal in for oscillator
VDD(OSC_PLL)
55
1.8 V supply for oscillator and PLL
VSS(PLL)
56
ground for PLL
VDD(IO)
57
3.3 V power supply for I/O
P1[3]/SCS2[1]/
PMAT3[3]
58[1]
GPIO1, pin 3
SPI2 SCS1
PWM3 MAT3
-
P1[2]/SCS2[3]/
PMAT3[2]
59[1]
GPIO1, pin 2
SPI2 SCS3
PWM3 MAT2
-
P1[1]/EI1/PMAT3[1]
60[1]
GPIO1, pin 1
EXTINT1
PWM3 MAT1
-
VSS(CORE)
61
ground for digital core
VDD(CORE)
62
1.8 V power supply for digital core
P1[0]/EI0/PMAT3[0]
63[1]
GPIO1, pin 0
EXTINT0
PWM3 MAT0
-
P0[0]/PHB0/
TXDC0/D24
64[1]
GPIO0, pin 0
QEI0 PHB
CAN0 TXD
-
VSS(IO)
65
ground for I/O
P0[1]/PHA0/RXDC0
66[1]
GPIO0, pin 1
QEI0 PHA
CAN0 RXD
-
P0[2]/CLK_OUT/
PMAT0[0]
67[1]
GPIO0, pin 2
CLK_OUT
PWM0 MAT0
-
P0[3]/USB_UP_LED/ 68[1]
PMAT0[1]
GPIO0, pin 3
USB_UP_LED
PWM0 MAT1
-
P0[4]/PMAT0[2]
69[1]
GPIO0, pin 4
-
PWM0 MAT2
-
P0[5]/PMAT0[3]
70[1]
GPIO0, pin 5
-
PWM0 MAT3
-
VDD(IO)
71
3.3 V power supply for I/O
P0[6]/PMAT0[4]
72[1]
GPIO0, pin 6
-
PWM0 MAT4
-
P0[7]/PMAT0[5]
73[1]
GPIO0, pin 7
-
PWM0 MAT5
-
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LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
Table 3.
LQFP100 pin assignment …continued
Pin name
Pin
Description
Function 0 (default)
Function 1
Function 2
Function 3
VDDA(ADC3V3)
74
3.3 V power supply for ADC
JTAGSEL
75[1]
TAP controller select input; LOW-level selects the ARM debug mode; HIGH-level selects
boundary scan; pulled up internally.
n.c.
76
not connected to a function; must be tied to 3.3 V power supply for ADC VDDA(ADC3V3).
VREFP
77[3]
HIGH reference for ADC
VREFN
78[3]
LOW reference for ADC
P0[8]/IN1[0]
79[4]
GPIO0, pin 8
ADC1 IN0
-
-
P0[9]/IN1[1]
80[4]
GPIO0, pin 9
ADC1 IN1
-
-
P0[10]/IN1[2]/
PMAT1[0]
81[4]
GPIO0, pin 10
ADC1 IN2
PWM1 MAT0
-
P0[11]/IN1[3]/
PMAT1[1]
82[4]
GPIO0, pin 11
ADC1 IN3
PWM1 MAT1
-
VSS(IO)
83
ground for I/O
P0[12]/IN1[4]/
PMAT1[2]
84[4]
GPIO0, pin 12
ADC1 IN4
PWM1 MAT2
-
P0[13]/IN1[5]/
PMAT1[3]
85[4]
GPIO0, pin 13
ADC1 IN5
PWM1 MAT3
-
P0[14]/IN1[6]/
PMAT1[4]
86[4]
GPIO0, pin 14
ADC1 IN6
PWM1 MAT4
-
P0[15]/IN1[7]/
PMAT1[5]
87[4]
GPIO0, pin 15
ADC1 IN7
PWM1 MAT5
-
P0[16]IN2[0]/TXD0
88[4]
GPIO0, pin 16
ADC2 IN0
UART0 TXD
-
P0[17]/IN2[1]/
RXD0/A23
89[4]
GPIO0, pin 17
ADC2 IN1
UART0 RXD
-
VDD(CORE)
90
1.8 V power supply for digital core
VSS(CORE)
91
ground for digital core
VDD(IO)
92
3.3 V power supply for I/O
P0[18]/IN2[2]/
PMAT2[0]
93[4]
GPIO0, pin 18
ADC2 IN2
PWM2 MAT0
-
P0[19]/IN2[3]/
PMAT2[1]
94[4]
GPIO0, pin 19
ADC2 IN3
PWM2 MAT1
-
P0[20]/IN2[4]/
PMAT2[2]
95[4]
GPIO0, pin 20
ADC2 IN4
PWM2 MAT2
-
P0[21]/IN2[5]/
PMAT2[3]
96[4]
GPIO0, pin 21
ADC2 IN5
PWM2 MAT3
-
P0[22]/IN2[6]/
PMAT2[4]/A18
97[4]
GPIO0, pin 22
ADC2 IN6
PWM2 MAT4
-
VSS(IO)
98
ground for I/O
LPC2921_23_25_3
Product data sheet
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Rev. 03 — 14 April 2010
© NXP B.V. 2010. All rights reserved.
8 of 84
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
Table 3.
LQFP100 pin assignment …continued
Pin name
Pin
Function 0 (default)
Function 1
Function 2
Function 3
P0[23]/IN2[7]/
PMAT2[5]/A19
99[4]
GPIO0, pin 23
ADC2 IN7
PWM2 MAT5
-
TDI
100[1]
IEEE 1149.1 data in, pulled up internally
[1]
Description
Bidirectional pad; analog port; plain input; 3-state output; slew rate control; 5 V tolerant; TTL with hysteresis; programmable
pull-up/pull-down/repeater.
[2]
USB pad.
[3]
Analog pad; analog I/O.
[4]
Analog I/O pad.
6. Functional description
6.1 Architectural overview
The LPC2921/2923/2925 consists of:
• An ARM968E-S processor with real-time emulation support
• An AMBA multilayer Advanced High-performance Bus (AHB) for interfacing to the
on-chip memory controllers
• Two DTL buses (an universal NXP interface) for interfacing to the interrupt controller
and the Power, Clock and Reset control SubSystem (PCRSS).
• Three ARM Peripheral Buses (APB - a compatible super set of ARM's AMBA
advanced peripheral bus) for connection to on-chip peripherals clustered in
subsystems.
• One ARM Peripheral Bus for event router and system control.
The LPC2921/2923/2925 configures the ARM968E-S processor in little-endian byte order.
All peripherals run at their own clock frequency to optimize the total system power
consumption. The AHB-to-APB bridge used in the subsystems contains a write-ahead
buffer one transaction deep. This implies that when the ARM968E-S issues a buffered
write action to a register located on the APB side of the bridge, it continues even though
the actual write may not yet have taken place. Completion of a second write to the same
subsystem will not be executed until the first write is finished.
6.2 ARM968E-S processor
The ARM968E-S is a general purpose 32-bit RISC processor, which offers high
performance and very low power consumption. The ARM architecture is based on
Reduced Instruction Set Computer (RISC) principles, and the instruction set and related
decode mechanism are much simpler than those of microprogrammed Complex
Instruction Set Computers (CISC). This simplicity results in a high instruction throughput
and impressive real-time interrupt response from a small and cost-effective controller
core.
Amongst the most compelling features of the ARM968E-S are:
• Separate directly connected instruction and data Tightly Coupled Memory (TCM)
interfaces.
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• Write buffers for the AHB and TCM buses.
• Enhanced 16 × 32 multiplier capable of single-cycle MAC operations and 16-bit fixedpoint DSP instructions to accelerate signal-processing algorithms and applications.
Pipeline techniques are employed so that all parts of the processing and memory systems
can operate continuously. The ARM968E-S is based on the ARMv5TE five-stage pipeline
architecture. Typically, in a three-stage pipeline architecture, while one instruction is being
executed its successor is being decoded and a third instruction is being fetched from
memory. In the five-stage pipeline additional stages are added for memory access and
write-back cycles.
The ARM968E-S processor also employs a unique architectural strategy known as
THUMB, which makes it ideally suited to high-volume applications with memory
restrictions or to applications where code density is an issue.
The key idea behind THUMB is that of a super-reduced instruction set. Essentially, the
ARM968E-S processor has two instruction sets:
• Standard 32-bit ARMv5TE set
• 16-bit THUMB set
The THUMB set's 16-bit instruction length allows it to approach twice the density of
standard ARM code while retaining most of the ARM's performance advantage over a
traditional 16-bit controller using 16-bit registers. This is possible because THUMB code
operates on the same 32-bit register set as ARM code.
THUMB code can provide up to 65 % of the code size of ARM, and 160 % of the
performance of an equivalent ARM controller connected to a 16-bit memory system.
The ARM968E-S processor is described in detail in the ARM968E-S data sheet Ref. 2.
6.3 On-chip flash memory system
The LPC2921/2923/2925 includes a 128 kB, 256 kB, or 512 kB flash memory system.
This memory can be used for both code and data storage. Programming of the flash
memory can be accomplished via the flash memory controller or the JTAG.
The flash controller also supports a 16 kB, byte-accessible on-chip EEPROM integrated
on the LPC2921/2923/2925.
6.4 On-chip static RAM
In addition to the two 16 kB TCMs, the LPC2921/2923/2925 includes two static RAM
memories of 16 kB each for a total of 32 kB (LPC2925 only) or one block of 16 kB
(LPC2921/2923). They may be used for code and/or data storage.
The 8 kB SRAM block for the ETB can be used as static memory for code and data
storage as well. However, DMA access to this memory region is not supported.
LPC2921_23_25_3
Product data sheet
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xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx xxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
4 GB
LPC2921/2923/2925
0xFFFF FFFF
0xFFFF F000
0xFFFF C000
PCR/VIC control
VIC
reserved
0xFFFF B000
CGU1
0xFFFF A000
PMU
0xFFFF 9000
0xFFFF 8000
reserved
PCR/VIC
subsystem
DMA interface to TCM
reserved
RGU
CGU0
0xE00E 0000
0xE008 6000
reserved
USB controller
0xE008 4000
0xE010 0000
I2C1
0xE008 3000
0xE00E 0000
I2C0
0xE008 2000
CAN1
0xE008 1000
CAN0
0xE008 0000
0xE00C 0000
reserved
peripherals #6
MSCSS
subsystem
0xE00A 0000
peripheral subsystem #4
reserved
0xE00C 3000
ADC1
peripheral subsystem #2
0xE00C 2000
reserved
reserved
MSCSS timer1
peripheral subsystem #0
0xE00C 1000
0xE00C 0000
0xE008 7000
0xE014 0000
ADC2
0xE00C 4000
0xE008 8000
CAN AF regs
MSCSS timer0
0xE006 0000
reserved
0xE006 0000
GPIO5
0xE005 0000
0xE004 F000
0xE004 0000
reserved
0xE004 C000
GPIO1
0xE004 B000
GPIO0
0xE004 A000
SPI2
0xE004 9000
SPI1
0xE004 8000
SPI0
0xE004 7000
0x8000 4000
UART1
0xE004 6000
0x8000 0000
UART0
0xE004 5000
0xE002 0000
0xE000 0000
reserved
0x2008 0000
remappable to
shadow area
reserved
flash controller
reserved
16 kB AHB SRAM (LPC2925 only)
flash
memory
2 GB
16 kB AHB SRAM
0x8000 8000
peripherals #2
peripheral
subsystem
0x2004 0000
512 kB on-chip flash
TIMER3
0xE004 4000
0x2002 0000
256 kB on-chip flash
TIMER2
0xE004 3000
0x2000 0000
128 kB on-chip flash
TIMER1
0xE004 2000
TIMER0
0xE004 1000
WDT
0xE004 0000
reserved
0x2000 0000
0x0080 0000
0x0040 4000
11 of 84
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0x0040 0000
no physical
memory
reserved
16 kB DTCM
1 GB
ITCM/DTCM
memory
0x4000 0000
reserved
on-chip flash
reserved
0x2000 0000
0x0000 4000
0x0000 0000
Fig 3.
0x2020 4000
512 MB shadow area
ITCM/DTCM
16 kB ITCM
LPC2921/2923/2925 memory map
0 GB
0x0000 0000
0xE002 0000
peripherals #0
general
subsystem
reserved
event router
0xE000 3000
0xE000 2000
SCU
0xE000 1000
CFID
0xE000 0000
002aae232
LPC2921/2923/2925
0xE008 0000
0x8000 C000
0x2020 4000
0x2020 0000
peripherals #4
networking
subsystem
ARM9 microcontroller with CAN, LIN, and USB
Rev. 03 — 14 April 2010
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PWM0
0xE008 9000
CAN common regs
0xE018 3000
DMA controller
0xE00C 8000
0xE00C 5000
LIN0
CAN ID LUT
peripheral subsystem #6
0xE00C 6000
0xE008 A000
0xF000 0000
0xE018 0000
PWM3
PWM1
LIN1
8 kB ETB SRAM
0xE00C 9000
0xE00C 7000
0xE008 B000
0xF080 0000
0xE018 2000
reserved
PWM2
0xE00A 0000
reserved
ETB control
reserved
quadrature encoder
0xE00C A000
0xFFFF FFFF
0xFFFF 8000
NXP Semiconductors
LPC2921_23_25_3
Product data sheet
6.5 Memory map
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
6.6 Reset, debug, test, and power description
6.6.1 Reset and power-up behavior
The LPC2921/2923/2925 contains external reset input and internal power-up reset
circuits. This ensures that a reset is extended internally until the oscillators and flash have
reached a stable state. See Section 8 for trip levels of the internal power-up reset circuit1.
See Section 9 for characteristics of the several start-up and initialization times. Table 4
shows the reset pin.
Table 4.
Reset pin
Symbol
Direction
Description
RST
IN
external reset input, active LOW; pulled up internally
At activation of the RST pin the JTAGSEL pin is sensed as logic LOW. If this is the case
the LPC2921/2923/2925 is assumed to be connected to debug hardware, and internal
circuits re-program the source for the BASE_SYS_CLK to be the crystal oscillator instead
of the Low-Power Ring Oscillator (LP_OSC). This is required because the clock rate when
running at LP_OSC speed is too low for the external debugging environment.
6.6.2 Reset strategy
The LPC2921/2923/2925 contains a central module, the Reset Generator Unit (RGU) in
the Power, Clock and Reset control Subsystem (PCRSS), which controls all internal reset
signals towards the peripheral modules. The RGU provides individual reset control as well
as the monitoring functions needed for tracing a reset back to source.
6.6.3 IEEE 1149.1 interface pins (JTAG boundary-scan test)
The LPC2921/2923/2925 contains boundary-scan test logic according to IEEE 1149.1,
also referred to in this document as Joint Test Action Group (JTAG). The boundary-scan
test pins can be used to connect a debugger probe for the embedded ARM processor. Pin
JTAGSEL selects between boundary-scan mode and debug mode. Table 5 shows the
boundary-scan test pins.
Table 5.
1.
IEEE 1149.1 boundary-scan test and debug interface
Symbol
Description
JTAGSEL
TAP controller select input. LOW level selects ARM debug mode and HIGH level
selects boundary scan and flash programming; pulled up internally
TRST
test reset input; pulled up internally (active LOW)
TMS
test mode select input; pulled up internally
TDI
test data input, pulled up internally
TDO
test data output
TCK
test clock input
Only for 1.8 V power sources
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6.6.3.1
ETM/ETB
The ETM provides real-time trace capability for deeply embedded processor cores. It
outputs information about processor execution to a trace buffer. A software debugger
allows configuration of the ETM using a JTAG interface and displays the trace information
that has been captured in a format that a user can easily understand. The ETB stores
trace data produced by the ETM.
The ETM/ETB module has the following features:
•
•
•
•
•
Closely tracks the instructions that the ARM core is executing.
On-chip trace data storage (ETB).
All registers are programmed through JTAG interface.
Does not consume power when trace is not being used.
THUMB/Java instruction set support.
6.6.4 Power supply pins
Table 6 shows the power supply pins.
Table 6.
Power supply pins
Symbol
Description
VDD(CORE)
digital core supply 1.8 V
VSS(CORE)
digital core ground (digital core, ADC1/2)
VDD(IO)
I/O pins supply 3.3 V
VSS(IO)
I/O pins ground
VDD(OSC_PLL)
oscillator and PLL supply
VSS(OSC)
oscillator ground
VSS(PLL)
PLL ground
VDDA(ADC3V3)
ADC1 and ADC2 3.3 V supply
6.7 Clocking strategy
6.7.1 Clock architecture
The LPC2921/2923/2925 contains several different internal clock areas. Peripherals like
timers, SPI, UART, CAN and LIN have their own individual clock sources called base
clocks. All base clocks are generated by the Clock Generator Unit (CGU0). They may be
unrelated in frequency and phase and can have different clock sources within the CGU.
The system clock for the CPU and AHB Bus infrastructure has its own base clock. This
means most peripherals are clocked independently from the system clock. See Figure 4
for an overview of the clock areas within the device.
Within each clock area there may be multiple branch clocks, which offers very flexible
control for power-management purposes. All branch clocks are outputs of the Power
Management Unit (PMU) and can be controlled independently. Branch clocks derived
from the same base clock are synchronous in frequency and phase. See Section 6.15 for
more details of clock and power control within the device.
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Two of the base clocks generated by the CGU0 are used as input into a second,
dedicated CGU (CGU1). The CGU1 uses its own PLL and fractional dividers to generate
the base clock for the USB controller and one base clock for an independent clock output.
BASE_SYS_CLK
BASE_ICLK0_CLK
BASE_ICLK1_CLK
BASE_USB_CLK
USB
CPU
AHB MULTILAYER MATRIX
BASE_OUT_CLK
CLOCK
OUT
AHB TO APB BRIDGES
CGU1
VIC
BASE_IVNSS_CLK
networking subsystem
GPDMA
branch
clocks
FLASH/SRAM
CAN0/1
USB REGISTERS
branch
clocks
general subsytem
GLOBAL
ACCEPTANCE
FILTER
LIN0/1
SYSTEM CONTROL
EVENT ROUTER
CFID
I2C0/1
BASE_PCR_CLK
peripheral subsystem
power control subsystem
branch
clock
GPIO0/1/5
BASE_TMR_CLK
RESET/CLOCK
GENERATION
POWER
MANAGEMENT
BASE_MSCSS_CLK
TIMER0/1/2/3
BASE_SPI_CLK
modulation and sampling
control subsystem
SPI0/1/2
BASE_UART_CLK
TIMER0/1 MTMR
UART0/1
BASE_SAFE_CLK
WDT
branch
clocks
PWM0/1/2/3
QEI
BASE_ADC_CLK
ADC1/2
branch
clocks
CGU0
002aae238
Fig 4.
LPC2921/2923/2925 overview of clock areas
6.7.2 Base clock and branch clock relationship
Table 7 contains an overview of all the base blocks in the LPC2921/2923/2925 and their
derived branch clocks. A short description is given of the hardware parts that are clocked
with the individual branch clocks. In relevant cases more detailed information can be
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ARM9 microcontroller with CAN, LIN, and USB
found in the specific subsystem description. Some branch clocks have special protection
since they clock vital system parts of the device and should not be switched off. See
Section 6.15.5 for more details of how to control the individual branch clocks.
Table 7.
LPC2921_23_25_3
Product data sheet
Base clock and branch clock overview
Base clock
Branch clock name
Parts of the device clocked
by this branch clock
Remark
BASE_SAFE_CLK
CLK_SAFE
watchdog timer
[1]
BASE_SYS_CLK
CLK_SYS_CPU
ARM968E-S and TCMs
CLK_SYS_SYS
AHB bus infrastructure
CLK_SYS_PCRSS
AHB side of bridge in PCRSS
CLK_SYS_FMC
Flash Memory Controller
CLK_SYS_RAM0
Embedded SRAM Controller 0
(16 kB)
CLK_SYS_RAM1
Embedded SRAM Controller 1
(16 kB) (LPC2925 only)
CLK_SYS_GESS
General Subsystem
CLK_SYS_VIC
Vectored Interrupt Controller
CLK_SYS_PESS
Peripheral Subsystem
CLK_SYS_GPIO0
GPIO bank 0
CLK_SYS_GPIO1
GPIO bank 1
CLK_SYS_GPIO5
GPIO bank 5
CLK_SYS_IVNSS_A
AHB side of bridge of IVNSS
CLK_SYS_MSCSS_A
AHB side of bridge of MSCSS
CLK_SYS_DMA
GPDMA
CLK_SYS_USB
USB registers
BASE_PCR_CLK
CLK_PCR_SLOW
PCRSS, CGU, RGU and PMU
logic clock
BASE_IVNSS_CLK
CLK_IVNSS_APB
APB side of the IVNSS
CLK_IVNSS_CANCA
CAN controller Acceptance
Filter
CLK_IVNSS_CANC0
CAN channel 0
CLK_IVNSS_CANC1
CAN channel 1
CLK_IVNSS_I2C0
I2C0
CLK_IVNSS_I2C1
I2C1
CLK_IVNSS_LIN0
LIN channel 0
CLK_IVNSS_LIN1
LIN channel 1
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Rev. 03 — 14 April 2010
[2] [3]
[1] [4]
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Table 7.
Base clock and branch clock overview …continued
Base clock
Branch clock name
Parts of the device clocked
by this branch clock
BASE_MSCSS_CLK
CLK_MSCSS_APB
APB side of the MSCSS
CLK_MSCSS_MTMR0
Timer 0 in the MSCSS
CLK_MSCSS_MTMR1
Timer 1 in the MSCSS
CLK_MSCSS_PWM0
PWM0
CLK_MSCSS_PWM1
PWM1
CLK_MSCSS_PWM2
PWM2
CLK_MSCSS_PWM3
PWM3
Remark
CLK_MSCSS_ADC1_APB APB side of ADC1
CLK_MSCSS_ADC2_APB APB side of ADC2
CLK_MSCSS_QEI
Quadrature encoder
CLK_UART0
UART0 interface clock
CLK_UART1
UART1 interface clock
BASE_ICLK0_CLK
-
clock for CGU1 input
BASE_SPI_CLK
CLK_SPI0
SPI0 interface clock
CLK_SPI1
SPI1 interface clock
CLK_SPI2
SPI2 interface clock
CLK_TMR0
Timer 0 clock for counter part
CLK_TMR1
Timer 1 clock for counter part
CLK_TMR2
Timer 2 clock for counter part
CLK_TMR3
Timer 3 clock for counter part
CLK_ADC1
Control of ADC1, capture
sample result
CLK_ADC2
Control of ADC2, capture
sample result
reserved
-
-
BASE_ICLK1_CLK
-
clock for CGU1 input
BASE_UART_CLK
BASE_TMR_CLK
BASE_ADC_CLK
[1]
This clock is always on (cannot be switched off for system safety reasons)
[2]
In the peripheral subsystem parts of the timers, watchdog timer, SPI and UART have their own clock
source. See Section 6.12 for details.
[3]
The clock should remain activated when system wake-up on timer or UART is required.
[4]
In the Power, Clock and Reset control SubSystem (PCRSS) parts of the CGU, RGU, and PMU have their
own clock source. See Section 6.15 for details.
Table 8.
LPC2921_23_25_3
Product data sheet
CGU1 base clock and branch clock overview
Base clock
Branch clock name
Parts of the device clocked by this
branch clock
BASE_OUT_CLK
CLK_OUT_CLK
clock out pin
BASE_USB_CLK
CLK_USB_CLK
USB clock
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6.8 Flash memory controller
The flash memory has a 128-bit wide data interface and the flash controller offers two
128-bit buffer lines to improve system performance. The flash has to be programmed
initially via JTAG. In-system programming must be supported by the bootloader. Flash
memory contents can be protected by disabling JTAG access. Suspension of burning or
erasing is not supported.
The Flash Memory Controller (FMC) interfaces to the embedded flash memory for two
tasks:
• Memory data transfer
• Memory configuration via triggering, programming, and erasing
The key features are:
•
•
•
•
Programming by CPU via AHB
Programming by external programmer via JTAG
JTAG access protection
Burn-finished and erase-finished interrupt
6.8.1 Functional description
After reset flash initialization is started. During this initialization, flash access is not
possible and AHB transfers to flash are stalled, blocking the AHB bus.
During flash initialization, the index sector is read to identify the status of the JTAG access
protection and sector security. If JTAG access protection is active, the flash is not
accessible via JTAG. In this case, ARM debug facilities are disabled and flash memory
contents cannot be read. If sector security is active, only the unsecured sections can be
read.
Flash can be read synchronously or asynchronously to the system clock. In synchronous
operation, the flash goes into standby after returning the read data. Started reads cannot
be stopped, and speculative reading and dual buffering are therefore not supported.
With asynchronous reading, transfer of the address to the flash and of read data from the
flash is done asynchronously, giving the fastest possible response time. Started reads can
be stopped, so speculative reading and dual buffering are supported.
Buffering is offered because the flash has a 128-bit wide data interface while the AHB
interface has only 32 bits. With buffering a buffer line holds the complete 128-bit flash
word, from which four words can be read. Without buffering every AHB data port read
starts a flash read. A flash read is a slow process compared to the minimum AHB cycle
time, so with buffering the average read time is reduced improving system performance.
With single buffering, the most recently read flash word remains available until the next
flash read. When an AHB data-port read transfer requires data from the same flash word
as the previous read transfer, no new flash read is done and the read data is given without
wait cycles.
When an AHB data port read transfer requires data from a different flash word to that
involved in the previous read transfer, a new flash read is done and wait states are given
until the new read data is available.
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With dual buffering, a secondary buffer line is used, the output of the flash being
considered as the primary buffer. On a primary buffer, hit data can be copied to the
secondary buffer line, which allows the flash to start a speculative read of the next flash
word.
Both buffer lines are invalidated after:
•
•
•
•
Initialization
Configuration-register access
Data-latch reading
Index-sector reading
The modes of operation are listed in Table 9.
Table 9.
Flash read modes
Synchronous timing
No buffer line
for single (non-linear) reads; one flash-word read per word read
Single buffer line
default mode of operation; most recently read flash word is kept until
another flash word is required
Asynchronous timing
No buffer line
one flash-word read per word read
Single buffer line
most recently read flash word is kept until another flash word is
required
Dual buffer line, single
speculative
on a buffer miss a flash read is done, followed by at most one
speculative read; optimized for execution of code with small loops
(less than eight words) from flash
Dual buffer line, always
speculative
most recently used flash word is copied into second buffer line; next
flash-word read is started; highest performance for linear reads
6.8.2 Flash layout
The ARM processor can program the flash for ISP (In-System Programming) through the
flash memory controller. Note that the flash always has to be programmed by ‘flash words’
of 128 bits (four 32-bit AHB bus words, hence 16 bytes).
The flash memory is organized into eight ‘small’ sectors of 8 kB each and up to 11 ‘large’
sectors of 64 kB each. The number of large sectors depends on the device type. A sector
must be erased before data can be written to it. The flash memory also has sector-wise
protection. Writing occurs per page which consists of 4096 bits (32 flash words). A small
sector contains 16 pages; a large sector contains 128 pages.
Table 10 gives an overview of the flash-sector base addresses.
Table 10.
LPC2921_23_25_3
Product data sheet
Flash sector overview
Flash memory Sector size (kB)
sector number
Flash memory
address
LPC2921
LPC2923 LPC2925
11
8
0x2000 0000
yes
yes
yes
12
8
0x2000 2000
yes
yes
yes
13
8
0x2000 4000
yes
yes
yes
14
8
0x2000 6000
yes
yes
yes
15
8
0x2000 8000
yes
yes
yes
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Table 10.
Flash sector overview …continued
Flash memory Sector size (kB)
sector number
Flash memory
address
LPC2921
LPC2923 LPC2925
16
8
0x2000 A000
yes
yes
yes
17
8
0x2000 C000
yes
yes
yes
18
8
0x2000 E000
yes
yes
yes
0
64
0x2001 0000
yes
yes
yes
1
64
0x2002 0000
no
yes
yes
2
64
0x2003 0000
no
yes
yes
3
64
0x2004 0000
no
no
yes
4
64
0x2005 0000
no
no
yes
5
64
0x2006 0000
no
no
yes
6
64
0x2007 0000
no
no
yes
The index sector is a special sector in which the JTAG access protection and sector
security are located. The address space becomes visible by setting the FS_ISS bit and
overlaps the regular flash sector’s address space.
Note that the index sector, once programmed, cannot be erased. Any flash operation must
be executed out of SRAM (internal or external).
6.8.3 Flash bridge wait-states
To eliminate the delay associated with synchronizing flash-read data, a predefined
number of wait-states must be programmed. These depend on flash memory response
time and system clock period. The minimum wait-states value can be calculated with the
following formulas:
Synchronous reading:
t acc ( clk )
WST > ------------------ – 1
tt
(1)
tclk ( sys )
Asynchronous reading:
t acc ( addr )
WST > ---------------------- – 1
t tclk ( sys )
(2)
Remark: If the programmed number of wait-states is more than three, flash-data reading
cannot be performed at full speed (i.e. with zero wait-states at the AHB bus) if speculative
reading is active.
6.8.4 Pin description
The flash memory controller has no external pins. However, the flash can be programmed
via the JTAG pins, see Section 6.6.3.
6.8.5 Clock description
The flash memory controller is clocked by CLK_SYS_FMC, see Section 6.7.2.
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6.8.6 EEPROM
EEPROM is a non-volatile memory mostly used for storing relatively small amounts of
data, for example for storing settings. It contains one 16 kB memory block and is
byte-programmable and byte-erasable.
The EEPROM can be accessed only through the flash controller.
6.9 General Purpose DMA (GPDMA) controller
The GPDMA controller allows peripheral-to-memory, memory-to-peripheral,
peripheral-to-peripheral, and memory-to-memory transactions. Each DMA stream
provides unidirectional serial DMA transfers for a single source and destination. For
example, a bidirectional port requires one stream for transmit and one for receives. The
source and destination areas can each be either a memory region or a peripheral, and
can be accessed through the same AHB master or one area by each master.
The GPDMA controls eight DMA channels with hardware prioritization. The DMA
controller interfaces to the system via two AHB bus masters, each with a full 32-bit data
bus width. DMA operations may be set up for 8-bit, 16-bit, and 32-bit data widths, and can
be either big-endian or little-endian. Incrementing or non-incrementing addressing for
source and destination are supported, as well as programmable DMA burst size. Scatter
or gather DMA is supported through the use of linked lists. This means that the source
and destination areas do not have to occupy contiguous areas of memory.
6.9.1 DMA support for peripherals
The GPDMA supports the following peripherals: SPI0/1/2 and UART0/1. The GPDMA can
access both embedded SRAM blocks, both TCMs, external static memory, and flash
memory.
6.9.2 Clock description
The DMA controller is clocked by CLK_SYS_DMA derived from BASE_SYS_CLK, see
Section 6.7.2.
6.10 USB interface
The Universal Serial Bus (USB) is a 4-wire bus that supports communication between a
host and one or more (up to 127) peripherals. The bus supports hot plugging and dynamic
configuration of the devices. All transactions are initiated by the Host controller.
The LPC2921/2923/2925 USB interface includes a device controller with on-chip PHY for
device. Details on typical USB interfacing solutions can be found in Section 10.2.
6.10.1 USB device controller
The device controller enables 12 Mbit/s data exchange with a USB Host controller. It
consists of a register interface, serial interface engine, endpoint buffer memory, and a
DMA controller. The serial interface engine decodes the USB data stream and writes data
to the appropriate endpoint buffer. The status of a completed USB transfer or error
condition is indicated via status registers. An interrupt is also generated if enabled. When
enabled, the DMA controller transfers data between the endpoint buffer and the on-chip
SRAM.
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The USB device controller has the following features:
•
•
•
•
•
Fully compliant with USB 2.0 specification (full speed).
Supports 32 physical (16 logical) endpoints with a 2 kB endpoint buffer RAM.
Supports Control, Bulk, Interrupt and Isochronous endpoints.
Scalable realization of endpoints at run time.
Endpoint Maximum packet size selection (up to USB maximum specification) by
software at run time.
• Supports SoftConnect and GoodLink features.
• While USB is in the Suspend mode, the LPC2921/2923/2925 can enter the reduced
power mode and wake up on USB activity.
• Supports DMA transfers with the on-chip SRAM blocks on all non-control endpoints.
• Allows dynamic switching between CPU-controlled slave and DMA modes.
• Double buffer implementation for Bulk and Isochronous endpoints.
6.10.2 Pin description
Table 11.
USB device port pins
Pin name
Direction
Description
USB_VBUS
I
USB_VBUS status input. When this function is not enabled
via its corresponding PINSEL register, it is driven HIGH
internally.
USB_D+
I/O
positive differential data
USB_D−
I/O
negative differential data
USB_CONNECT
O
SoftConnect control signal
USB_UP_LED
O
GoodLink LED control signal
6.10.3 Clock description
Access to the USB registers is clocked by the CLK_SYS_USB, derived from
BASE_SYS_CLK, see Section 6.7.2. The CGU1 provides an independent base clock to
the USB block, BASE_USB_CLK (see Section 6.15.3).
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6.11 General subsystem
6.11.1 General subsystem clock description
The general subsystem is clocked by CLK_SYS_GESS, see Section 6.7.2.
6.11.2 Chip and feature identification
The Chip/Feature ID (CFID) module contains registers which show and control the
functionality of the chip. It contains an ID to identify the silicon and also registers
containing information about the features enabled or disabled on the chip.
The key features are:
• Identification of product
• Identification of features enabled
The CFID has no external pins.
6.11.3 System Control Unit (SCU)
The system control unit contains system-related functions.The key feature is configuration
of the I/O port-pins multiplexer. It defines the function of each I/O pin of the
LPC2921/2923/2925. The I/O pin configuration should be consistent with peripheral
function usage.
The SCU has no external pins.
6.11.4 Event router
The event router provides bus-controlled routing of input events to the vectored interrupt
controller for use as interrupt or wake-up signals.
Key features:
• Up to 16 level-sensitive external interrupt pins, including the receive pins of SPI, CAN,
LIN, and UART, as well as the I2C-bus SCL pins plus three internal event sources.
• Input events can be used as interrupt source either directly or latched
(edge-detected).
•
•
•
•
•
Direct events disappear when the event becomes inactive.
Latched events remain active until they are explicitly cleared.
Programmable input level and edge polarity.
Event detection maskable.
Event detection is fully asynchronous, so no clock is required.
The event router allows the event source to be defined, its polarity and activation type to
be selected and the interrupt to be masked or enabled. The event router can be used to
start a clock on an external event.
The vectored interrupt-controller inputs are active HIGH.
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6.11.4.1
Pin description
The event router module in the LPC2921/2923/2925 is connected to the pins listed below.
The pins are combined with other functions on the port pins of the LPC2921/2923/2925.
Table 12 shows the pins connected to the event router.
Table 12.
Event-router pin connections
Symbol
Direction
Description
Default polarity
EXTINT[0:3]
I
external interrupt inputs 0 to 3
1
CAN0 RXD
I
CAN0 receive data input wake-up
0
CAN1 RXD
I
CAN1 receive data input wake-up
0
I2C0_SCL
I
I2C0
SCL clock input
0
I2C1_SCL
I
I2C1 SCL clock input
0
LIN0 RXD
I
LIN0 receive data input wake-up
0
LIN1 RXD
I
LIN1 receive data input wake-up
0
SPI0 SDI
I
SPI0 receive data input
0
SPI1 SDI
I
SPI1 receive data input
0
SPI2 SDI
I
SPI2 receive data input
0
UART0 RXD
I
UART0 receive data input
0
UART1 RXD
I
UART1 receive data input
0
-
n/a
CAN interrupt (internal)
1
-
n/a
VIC FIQ (internal)
1
-
n/a
VIC IRQ (internal)
1
6.12 Peripheral subsystem
6.12.1 Peripheral subsystem clock description
The peripheral subsystem is clocked by a number of different clocks:
•
•
•
•
•
CLK_SYS_PESS
CLK_UART0/1
CLK_SPI0/1/2
CLK_TMR0/1/2/3
CLK_SAFE see Section 6.7.2
6.12.2 Watchdog timer
The purpose of the watchdog timer is to reset the ARM9 processor within a reasonable
amount of time if the processor enters an error state. The watchdog generates a system
reset if the user program fails to trigger it correctly within a predetermined amount of time.
Key features:
•
•
•
•
LPC2921_23_25_3
Product data sheet
Internal chip reset if not periodically triggered
Timer counter register runs on always-on safe clock
Optional interrupt generation on watchdog time-out
Debug mode with disabling of reset
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• Watchdog control register change-protected with key
• Programmable 32-bit watchdog timer period with programmable 32-bit prescaler.
6.12.2.1
Functional description
The watchdog timer consists of a 32-bit counter with a 32-bit prescaler.
The watchdog should be programmed with a time-out value and then periodically
restarted. When the watchdog times out, it generates a reset through the RGU.
To generate watchdog interrupts in watchdog debug mode the interrupt has to be enabled
via the interrupt enable register. A watchdog-overflow interrupt can be cleared by writing
to the clear-interrupt register.
Another way to prevent resets during debug mode is via the Pause feature of the
watchdog timer. The watchdog is stalled when the ARM9 is in debug mode and the
PAUSE_ENABLE bit in the watchdog timer control register is set.
The Watchdog Reset output is fed to the Reset Generator Unit (RGU). The RGU contains
a reset source register to identify the reset source when the device has gone through a
reset. See Section 6.15.4.
6.12.2.2
Clock description
The watchdog timer is clocked by two different clocks; CLK_SYS_PESS and CLK_SAFE,
see Section 6.7.2. The register interface towards the system bus is clocked by
CLK_SYS_PESS. The timer and prescale counters are clocked by CLK_SAFE which is
always on.
6.12.3 Timer
The LPC2921/2923/2925 contains six identical timers: four in the peripheral subsystem
and two in the Modulation and Sampling Control SubSystem (MSCSS) located at different
peripheral base addresses. This section describes the four timers in the peripheral
subsystem. Each timer has four capture inputs and/or match outputs. Connection to
device pins depends on the configuration programmed into the port function-select
registers. The two timers located in the MSCSS have no external capture or match pins,
but the memory map is identical, see Section 6.14.6. One of these timers has an external
input for a pause function.
The key features are:
• 32-bit timer/counter with programmable 32-bit prescaler.
• Up to four 32-bit capture channels per timer. These take a snapshot of the timer value
when an external signal connected to the TIMERx CAPn input changes state. A
capture event may also optionally generate an interrupt.
• Four 32-bit match registers per timer that allow:
– Continuous operation with optional interrupt generation on match.
– Stop timer on match with optional interrupt generation.
– Reset timer on match with optional interrupt generation.
• Up to four external outputs per timer corresponding to match registers, with the
following capabilities:
– Set LOW on match.
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– Set HIGH on match.
– Toggle on match.
– Do nothing on match.
• Pause input pin (MSCSS timers only).
The timers are designed to count cycles of the clock and optionally generate interrupts or
perform other actions at specified timer values, based on four match registers. They also
include capture inputs to trap the timer value when an input signal changes state,
optionally generating an interrupt. The core function of the timers consists of a 32 bit
prescale counter triggering the 32 bit timer counter. Both counters run on clock
CLK_TMRx (x runs from 0 to 3) and all time references are related to the period of this
clock. Note that each timer has its individual clock source within the Peripheral
SubSystem. In the Modulation and Sampling SubSystem each timer also has its own
individual clock source. See Section 6.15.5 for information on generation of these clocks.
6.12.3.1
Pin description
The four timers in the peripheral subsystem of the LPC2921/2923/2925 have the pins
described below. The two timers in the modulation and sampling subsystem have no
external pins except for the pause pin on MSCSS timer 1. See Section 6.14.6 for a
description of these timers and their associated pins. The timer pins are combined with
other functions on the port pins of the LPC2921/2923/2925, see Section 6.11.3. Table
Table 13 shows the timer pins (x runs from 0 to 3).
Table 13.
Symbol
Pin name
Direction
Description
TIMERx CAP[0]
CAPx[0]
IN
TIMERx capture input 0[1]
TIMERx CAP[1]
CAPx[1]
IN
TIMERx capture input 1[1]
TIMERx CAP[2]
CAPx[2]
IN
TIMERx capture input 2
TIMERx CAP[3]
CAPx[3]
IN
TIMERx capture input 3
TIMERx MAT[0]
MATx[0]
OUT
TIMERx match output 0
TIMERx MAT[1]
MATx[1]
OUT
TIMERx match output 1
TIMERx MAT[2]
MATx[2]
OUT
TIMERx match output 2
TIMERx MAT[3]
MATx[3]
OUT
TIMERx match output 3
[1]
6.12.3.2
Timer pins
Note that CAP1[0] and CAP1[1] are not pinned out on Timer1.
Clock description
The timer modules are clocked by two different clocks; CLK_SYS_PESS and CLK_TMRx
(x = 0 to 3), see Section 6.7.2. Note that each timer has its own CLK_TMRx branch clock
for power management. The frequency of all these clocks is identical as they are derived
from the same base clock BASE_CLK_TMR. The register interface towards the system
bus is clocked by CLK_SYS_PESS. The timer and prescale counters are clocked by
CLK_TMRx.
6.12.4 UARTs
The LPC2921/2923/2925 contains two identical UARTs located at different peripheral
base addresses. The key features are:
• 16-byte receive and transmit FIFOs.
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•
•
•
•
Register locations conform to 550 industry standard.
Receiver FIFO trigger points at 1 byte, 4 bytes, 8 bytes and 14 bytes.
Built-in baud rate generator.
Support for RS-485/9-bit mode allows both software address detection and automatic
address detection using 9-bit mode.
The UART is commonly used to implement a serial interface such as RS232. The
LPC2921/2923/2925 contains two industry-standard 550 UARTs with 16-byte transmit and
receive FIFOs, but they can also be put into 450 mode without FIFOs.
Remark: The LIN controller can be configured to provide two additional standard UART
interfaces (see Section 6.13.2).
6.12.4.1
Pin description
The UART pins are combined with other functions on the port pins of the
LPC2921/2923/2925. Table 14 shows the UART pins (x runs from 0 to 1).
Table 14.
6.12.4.2
UART pins
Symbol
Pin name
Direction
Description
UARTx TXD
TXDx
OUT
UART channel x transmit data output
UARTx RXD
RXDx
IN
UART channel x receive data input
Clock description
The UART modules are clocked by two different clocks; CLK_SYS_PESS and
CLK_UARTx (x = 0 to 1), see Section 6.7.2. Note that each UART has its own
CLK_UARTx branch clock for power management. The frequency of all CLK_UARTx
clocks is identical since they are derived from the same base clock BASE_CLK_UART.
The register interface towards the system bus is clocked by CLK_SYS_PESS. The baud
generator is clocked by the CLK_UARTx.
6.12.5 Serial Peripheral Interface (SPI)
The LPC2921/2923/2925 contains three Serial Peripheral Interface modules (SPIs) to
allow synchronous serial communication with slave or master peripherals.
The key features are:
•
•
•
•
Master or slave operation.
Each SPI supports up to four slaves in sequential multi-slave operation.
Supports timer-triggered operation.
Programmable clock bit rate and prescale based on SPI source clock.
(BASE_SPI_CLK), independent of system clock.
• Separate transmit and receive FIFO memory buffers; 16 bits wide, 32 locations deep.
• Programmable choice of interface operation: Motorola SPI or Texas Instruments
Synchronous Serial Interfaces.
•
•
•
•
LPC2921_23_25_3
Product data sheet
Programmable data-frame size from 4 bits to 16 bits.
Independent masking of transmit FIFO, receive FIFO and receive overrun interrupts.
Serial clock-rate master mode: fserial_clk ≤ fclk(SPI) / 2.
Serial clock-rate slave mode: fserial_clk = fclk(SPI) / 4.
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• Internal loopback test mode.
The SPI module can operate in:
• Master mode:
– Normal transmission mode
– Sequential slave mode
• Slave mode
6.12.5.1
Functional description
The SPI module is a master or slave interface for synchronous serial communication with
peripheral devices that have either Motorola SPI or Texas Instruments Synchronous
Serial Interfaces.
The SPI module performs serial-to-parallel conversion on data received from a peripheral
device. The transmit and receive paths are buffered with FIFO memories
(16 bits wide × 32 words deep). Serial data is transmitted on pins SDOx and received on
pins SDIx.
The SPI module includes a programmable bit-rate clock divider and prescaler to generate
the SPI serial clock from the input clock CLK_SPIx.
The SPI module’s operating mode, frame format, and word size are programmed through
the SLVn_SETTINGS registers.
A single combined interrupt request SPI_INTREQ output is asserted if any of the
interrupts are asserted and unmasked.
Depending on the operating mode selected, the SPI SCS outputs operate as an
active-HIGH frame synchronization output for Texas Instruments synchronous serial
frame format or an active-LOW chip select for SPI.
Each data frame is between four and 16 bits long, depending on the size of words
programmed, and is transmitted starting with the MSB.
6.12.5.2
Pin description
The SPI pins are combined with other functions on the port pins of the
LPC2921/2923/2925, see Section 6.11.3. Table 15 shows the SPI pins (x runs from 0 to 2;
y runs from 0 to 3).
Table 15.
LPC2921_23_25_3
Product data sheet
SPI pins
Symbol
Pin name
Direction
Description
SPIx SCSy
SCSx[y]
IN/OUT
SPIx chip select[1][2]
SPIx SCK
SCKx
IN/OUT
SPIx clock[1]
SPIx SDI
SDIx
IN
SPIx data input
SPIx SDO
SDOx
OUT
SPIx data output
[1]
Direction of SPIx SCS and SPIx SCK pins depends on master or slave mode. These pins are output in
master mode, input in slave mode.
[2]
In slave mode there is only one chip select input pin, SPIx SCS0. The other chip selects have no function in
slave mode.
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6.12.5.3
Clock description
The SPI modules are clocked by two different clocks; CLK_SYS_PESS and CLK_SPIx
(x = 0, 1, 2), see Section 6.7.2. Note that each SPI has its own CLK_SPIx branch clock for
power management. The frequency of all clocks CLK_SPIx is identical as they are derived
from the same base clock BASE_CLK_SPI. The register interface towards the system bus
is clocked by CLK_SYS_PESS. The serial-clock rate divisor is clocked by CLK_SPIx.
The SPI clock frequency can be controlled by the CGU. In master mode the SPI clock
frequency (CLK_SPIx) must be set to at least twice the SPI serial clock rate on the
interface. In slave mode CLK_SPIx must be set to four times the SPI serial clock rate on
the interface.
6.12.6 General-purpose I/O
The LPC2921/2923/2925 contains two general-purpose I/O ports located at different
peripheral base addresses. All I/O pins are bidirectional, and the direction can be
programmed individually. The I/O pad behavior depends on the configuration
programmed in the port function-select registers.
The key features are:
•
•
•
•
6.12.6.1
General-purpose parallel inputs and outputs.
Direction control of individual bits.
Synchronized input sampling for stable input-data values.
All I/O pins default to input at reset to avoid any possible bus conflicts.
Functional description
The general-purpose I/O provides individual control over each bidirectional port pin. There
are two registers to control I/O direction and output level. The inputs are synchronized to
achieve stable read-levels.
To generate an open-drain output, set the bit in the output register to the desired value.
Use the direction register to control the signal. When set to output, the output driver
actively drives the value on the output. When set to input, the signal floats and can be
pulled up internally or externally.
6.12.6.2
Pin description
The five GPIO ports in the LPC2921/2923/2925 have the pins listed below. The GPIO pins
are combined with other functions on the port pins of the LPC2921/2923/2925. Table 16
shows the GPIO pins.
Table 16.
LPC2921_23_25_3
Product data sheet
GPIO pins
Symbol
Pin name
Direction
Description
GPIO0 pin[31:0]
P0[31:0]
IN/OUT
GPIO port x pins 31 to 0
GPIO1 pin[27:0]
P1[27:0]
IN/OUT
GPIO port x pins 27 to 0
GPIO5 pin[19:18]
P5[19:18]
IN/OUT
GPIO port x pins 19 and 18
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6.12.6.3
Clock description
The GPIO modules are clocked by several clocks, all of which are derived from
BASE_SYS_CLK; CLK_SYS_PESS and CLK_SYS_GPIOx (x = 0, 1, 5), see
Section 6.7.2. Note that each GPIO has its own CLK__SYS_GPIOx branch clock for
power management. The frequency of all clocks CLK_SYS_GPIOx is identical to
CLK_SYS_PESS since they are derived from the same base clock BASE_SYS_CLK.
6.13 Networking subsystem
6.13.1 CAN gateway
Controller Area Network (CAN) is the definition of a high-performance communication
protocol for serial data communication. The two CAN controllers in the
LPC2921/2923/2925 provide a full implementation of the CAN protocol according to the
CAN specification version 2.0B. The gateway concept is fully scalable with the number of
CAN controllers, and always operates together with a separate powerful and flexible
hardware acceptance filter.
The key features are:
•
•
•
•
•
•
•
•
6.13.1.1
Supports 11-bit as well as 29-bit identifiers.
Double receive buffer and triple transmit buffer.
Programmable error-warning limit and error counters with read/write access.
Arbitration-lost capture and error-code capture with detailed bit position.
Single-shot transmission (i.e. no re-transmission).
Listen-only mode (no acknowledge; no active error flags).
Reception of ‘own’ messages (self-reception request).
FullCAN mode for message reception.
Global acceptance filter
The global acceptance filter provides look-up of received identifiers - called acceptance
filtering in CAN terminology - for all the CAN controllers. It includes a CAN ID look-up table
memory, in which software maintains one to five sections of identifiers. The CAN ID
look-up table memory is 2 kB large (512 words, each of 32 bits). It can contain up to 1024
standard frame identifiers or 512 extended frame identifiers or a mixture of both types. It is
also possible to define identifier groups for standard and extended message formats.
6.13.1.2
Pin description
The two CAN controllers in the LPC2921/2923/2925 have the pins listed below. The CAN
pins are combined with other functions on the port pins of the LPC2921/2923/2925.
Table 17 shows the CAN pins (x runs from 0 to 1).
Table 17.
LPC2921_23_25_3
Product data sheet
CAN pins
Symbol
Pin name
Direction
Description
CANx TXD
TXDC0/1
OUT
CAN channel x transmit data output
CANx RXD
RXDC0/1
IN
CAN channel x receive data input
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6.13.2 LIN
The LPC2921/2923/2925 contain two LIN 2.0 master controllers. These can be used as
dedicated LIN 2.0 master controllers with additional support for sync break generation and
with hardware implementation of the LIN protocol according to spec 2.0.
The key features are:
•
•
•
•
•
•
•
•
•
•
6.13.2.1
Complete LIN 2.0 message handling and transfer
One interrupt per LIN message
Slave response time-out detection
Programmable sync-break length
Automatic sync-field and sync-break generation
Programmable inter-byte space
Hardware or software parity generation
Automatic checksum generation
Fault confinement
Fractional baud rate generator
Pin description
The two LIN 2.0 master controllers in the LPC2921/2923/2925 have the pins listed below.
The LIN pins are combined with other functions on the port pins of the
LPC2921/2923/2925. Table 18 shows the LIN pins. For more information see Ref. 1
subsection 3.43, LIN master controller.
Table 18.
LIN controller pins
Symbol
Pin name
Direction
Description
LIN0/1 TXD
TXDL0/1
OUT
LIN channel 0/1 transmit data output
LIN0/1 RXD
RXDL0/1
IN
LIN channel 0/1 receive data input
Remark: Both LIN channels can be also configured as UART channels.
6.13.3 I2C-bus serial I/O controllers
The LPC2921/2923/2925 each contain two I2C-bus controllers.
The I2C-bus is bidirectional for inter-IC control using only two wires: a Serial CLock line
(SCL) and a Serial DAta line (SDA). Each device is recognized by a unique address and
can operate as either a receiver-only device (e.g., an LCD driver) or as a transmitter with
the capability to both receive and send information (such as memory). Transmitters and/or
receivers can operate in either master or slave mode, depending on whether the chip has
to initiate a data transfer or is only addressed. The I2C is a multi-master bus, and it can be
controlled by more than one bus master connected to it.
The main features if the I2C-bus interfaces are:
• I2C0 and I2C1 use standard I/O pins with bit rates of up to 400 kbit/s (Fast I2C-bus)
and do not support powering off of individual devices connected to the same bus
lines.
• Easy to configure as master, slave, or master/slave.
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•
•
•
•
Programmable clocks allow versatile rate control.
Bidirectional data transfer between masters and slaves.
Multi-master bus (no central master).
Arbitration between simultaneously transmitting masters without corruption of serial
data on the bus.
• Serial clock synchronization allows devices with different bit rates to communicate via
one serial bus.
• Serial clock synchronization can be used as a handshake mechanism to suspend and
resume serial transfer.
• The I2C-bus can be used for test and diagnostic purposes.
• All I2C-bus controllers support multiple address recognition and a bus monitor mode.
6.13.3.1
Pin description
Table 19.
I2C-bus pins[1]
Symbol
Pin name
Direction
Description
I2C SCL0/1
SCL0/1
I/O
I2C clock input/output
I2C SDA0/1
SDA0/1
I/O
I2C data input/output
[1]
Note that the pins are not I2C-bus compliant open-drain pins.
6.14 Modulation and Sampling Control SubSystem (MSCSS)
The Modulation and Sampling Control Subsystem (MSCSS) in the LPC2921/2923/2925
includes four Pulse Width Modulators (PWMs), two 10-bit successive approximation
Analog-to-Digital Converters (ADCs) and two timers.
The key features of the MSCSS are:
• Two 10-bit, 400 ksample/s, 8-channel ADCs with 3.3 V inputs and various triggerstart options.
• Four 6-channel PWMs (Pulse Width Modulators) with capture and trap functionality.
• Two dedicated timers to schedule and synchronize the PWMs and ADCs.
• Quadrature encoder interface.
6.14.1 Functional description
The MSCSS contains Pulse Width Modulators (PWMs), Analog-to-Digital Converters
(ADCs) and timers.
Figure 5 provides an overview of the MSCSS. An AHB-to-APB bus bridge takes care of
communication with the AHB system bus. Two internal timers are dedicated to this
subsystem. MSCSS timer 0 can be used to generate start pulses for the ADCs and the
first PWM. The second timer (MSCSS timer 1) is used to generate ‘carrier’ signals for the
PWMs. These carrier patterns can be used, for example, in applications requiring current
control. Several other trigger possibilities are provided for the ADCs (external, cascaded
or following a PWM). The capture inputs of both timers can also be used to capture the
start pulse of the ADCs.
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The PWMs can be used to generate waveforms in which the frequency, duty cycle and
rising and falling edges can be controlled very precisely. Capture inputs are provided to
measure event phases compared to the main counter. Depending on the applications,
these inputs can be connected to digital sensor motor outputs or digital external signals.
Interrupt signals are generated on several events to closely interact with the CPU.
The ADCs can be used for any application needing accurate digitized data from analog
sources. To support applications like motor control, a mechanism to synchronize several
PWMs and ADCs is available (sync_in and sync_out).
Note that the PWMs run on the PWM clock and the ADCs on the ADC clock, see
Section 6.15.2.
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AHB-TO-APB BRIDGE
MSCSS
PHA0
PHB0
QEI
capture
start
ADC1 IN[7:0]
ADC1
MSCSS
TIMER0
ADC2 EXT START
start
ADC2 IN[7:0]
ADC2
start
PWM0 MAT[5:0]
PWM0
capture
carrier
synch
carrier
PWM1
PWM1 MAT[5:0]
PAUSE
MSCSS
TIMER1
synch
carrier
PWM2 MAT[5:0]
PWM2
synch
carrier
PWM3
PWM3 MAT[5:0]
PWM0 CAP[2:0]
PWM1 CAP[2:0]
PWM2 TRAP
PWM2 CAP[2:0]
PWM3 TRAP
PWM3 CAP[2:0]
002aae248
Fig 5.
Modulation and Sampling Control SubSystem (MSCSS) block diagram
6.14.2 Pin description
The pins of the LPC2921/2923/2925 MSCSS associated with the two ADC modules are
described in Section 6.14.4.2. Pins connected to the four PWM modules are described in
Section 6.14.5.4, pins directly connected to the MSCSS timer 1 module are described in
Section 6.14.6.1, and pins connected to the quadrature encoder interface are described in
Section 6.14.7.1.
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Remark: The IDX0 function for the QEI, the external start function for ADC1, and the
TRAP0/1 functions for the PWM0/1 are not pinned out on the LPC2921/2923/2925.
6.14.3 Clock description
The MSCSS is clocked from a number of different sources:
•
•
•
•
CLK_SYS_MSCSS_A clocks the AHB side of the AHB-to-APB bus bridge
CLK_MSCSS_APB clocks the subsystem APB bus
CLK_MSCSS_MTMR0/1 clocks the timers
CLK_MSCSS_PWM[0:3] clocks the PWMs.
Each ADC has two clock areas; an APB part clocked by CLK_MSCSS_ADCx_APB (x = 1
or 2) and a control part for the analog section clocked by CLK_ADCx = 1 or 2), see
Section 6.7.2.
All clocks are derived from the BASE_MSCSS_CLK, except for CLK_SYS_MSCSS_A
which is derived form BASE_SYS_CLK, and the CLK_ADCx clocks which are derived
from BASE_CLK_ADC. If specific PWM or ADC modules are not used their corresponding
clocks can be switched off.
6.14.4 Analog-to-digital converter
The MSCSS in the LPC2921/2923/2925 includes two 10-bit successive-approximation
analog-to-digital converters.
The key features of the ADC interface module are:
• ADC1 and ADC2: Eight analog inputs; time-multiplexed; measurement range up to
3.3 V.
• External reference-level inputs.
• 400 ksamples per second at 10-bit resolution up to 1500 ksamples per second at 2-bit
resolution.
• Programmable resolution from 2-bit to 10-bit.
• Single analog-to-digital conversion scan mode and continuous analog-to-digital
conversion scan mode.
• Optional conversion on transition on external start input, timer capture/match signal,
PWM_sync or ‘previous’ ADC.
• Converted digital values are stored in a register for each channel.
• Optional compare condition to generate a ‘less than’ or an ‘equal to or greater than’
compare-value indication for each channel.
• Power-down mode.
6.14.4.1
Functional description
The ADC block diagram, Figure 6, shows the basic architecture of each ADC. The ADC
functionality is divided into two major parts; one part running on the MSCSS Subsystem
clock, the other on the ADC clock. This split into two clock domains affects the behavior
from a system-level perspective. The actual analog-to-digital conversions take place in the
ADC clock domain, but system control takes place in the system clock domain.
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A mechanism is provided to modify configuration of the ADC and control the moment at
which the updated configuration is transferred to the ADC domain.
The ADC clock is limited to 4.5 MHz maximum frequency and should always be lower
than or equal to the system clock frequency. To meet this constraint or to select the
desired lower sampling frequency, the clock generation unit provides a programmable
fractional system-clock divider dedicated to the ADC clock. Conversion rate is determined
by the ADC clock frequency divided by the number of resolution bits plus one. Accessing
ADC registers requires an enabled ADC clock, which is controllable via the clock
generation unit, see Section 6.15.2.
Each ADC has four start inputs. Note that start 0 and start 2 are captured in the system
clock domain while start 1 and start 3 are captured in the ADC domain. The start inputs
are connected at MSCSS level, see Section 6.14 for details.
ADC clock
(up to 4.5 MHz)
(BASE_ADC_CLK)
APB clock
(BASE_MSCSS_CLK)
SYSTEM DOMAIN
ADC DOMAIN
3.3 V
ADC1
update
APB system bus
ADC
REGISTERS
IRQ scan
configuration data
IRQ compare
3.3 V
ADC2
ADC1 IN[7:0]
ANALOG
MUX
ADC2 IN[7:0]
3.3 V IN
IRQ
ADC
start 0
Fig 6.
ADC
CONTROL
conversion data
ANALOG
MUX
3.3 V IN
ADC
start 2
ADC
start 1
ADC
start 3
sync_out
002aad960
ADC block diagram
6.14.4.2
Pin description
The two ADC modules in the MSCSS have the pins described below. The ADCx input
pins are combined with other functions on the port pins of the LPC2921/2923/2925. The
VREFN and VREFP pins are common for both ADCs. Table 20 shows the ADC pins.
Table 20.
Analog to digital converter pins
Symbol
Pin name
Direction
Description
ADC1/2 IN[7:0]
IN1/2[7:0]
IN
analog input for 3.3 V ADC1/2, channel 7 to
channel 0
ADC2_EXT_START
CAP1[2]
IN
ADC external start-trigger input
VREFN
VREFN
IN
ADC LOW reference level
VREFP
VREFP
IN
ADC HIGH reference level
VDDA(ADC3V3)
VDDA(ADC3V3) IN
ADC1 and ADC2 3.3 V supply
Remark: Note that the ADC1 and ADC2 accept an input voltage up to of 3.6 V (see
Table 31) on the ADC1/2 IN pins. If the ADC is not used, the pins are 5 V tolerant.
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6.14.4.3
Clock description
The ADC modules are clocked from two different sources; CLK_MSCSS_ADCx_APB and
CLK_ADCx (x = 1 or 2), see Section 6.7.2. Note that each ADC has its own CLK_ADCx
and CLK_MSCSS_ADCx_APB branch clocks for power management. If an ADC is
unused both its CLK_MSCSS_ADCx_APB and CLK_ADCx can be switched off.
The frequency of all the CLK_MSCSS_ADCx_APB clocks is identical to
CLK_MSCSS_APB since they are derived from the same base clock
BASE_MSCSS_CLK. Likewise the frequency of all the CLK_ADCx clocks is identical
since they are derived from the same base clock BASE_ADC_CLK.
The register interface towards the system bus is clocked by CLK_MSCSS_ADCx_APB.
Control logic for the analog section of the ADC is clocked by CLK_ADCx, see also
Figure 6.
6.14.5 Pulse Width Modulator (PWM)
The MSCSS in the LPC2921/2923/2925 includes four PWM modules with the following
features.
•
•
•
•
•
•
Six pulse width modulated output signals
Double edge features (rising and falling edges programmed individually)
Optional interrupt generation on match (each edge)
Different operation modes: continuous or run-once
16-bit PWM counter and 16-bit prescale counter allow a large range of PWM periods
A protective mode (TRAP) holding the output in a software-controllable state and with
optional interrupt generation on a trap event
• Three capture registers and capture trigger pins with optional interrupt generation on
a capture event
• Interrupt generation on match event, capture event, PWM counter overflow or trap
event
• A burst mode mixing the external carrier signal with internally generated PWM
• Programmable sync-delay output to trigger other PWM modules (master/slave
behavior)
6.14.5.1
Functional description
The ability to provide flexible waveforms allows PWM blocks to be used in multiple
applications; e.g. dimmer/lamp control and fan control. Pulse width modulation is the
preferred method for regulating power since no additional heat is generated, and it is
energy-efficient when compared with linear-regulating voltage control networks.
The PWM delivers the waveforms/pulses of the desired duty cycles and cycle periods. A
very basic application of these pulses can be in controlling the amount of power
transferred to a load. Since the duty cycle of the pulses can be controlled, the desired
amount of power can be transferred for a controlled duration. Two examples of such
applications are:
• Dimmer controller: The flexibility of providing waves of a desired duty cycle and cycle
period allows the PWM to control the amount of power to be transferred to the load.
The PWM functions as a dimmer controller in this application.
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• Motor controller: The PWM provides multi-phase outputs, and these outputs can be
controlled to have a certain pattern sequence. In this way the force/torque of the
motor can be adjusted as desired. This makes the PWM function as a motor drive.
sync_in
transfer_enable_in
APB DOMAIN
PWM DOMAIN
update
APB system bus
match outputs
capture data
PWM
CONTROL
&
REGISTERS
IRQ pwm
IRQ capt_match
PWM,
COUNTER,
PRESCALE
COUNTER
&
SHADOW
REGISTERS
PWM counter value
config data
IRQs
capture inputs
trap input
carrier inputs
transfer_enable_out
sync_out
002aad837
Fig 7.
PWM block diagram
The PWM block diagram in Figure 7 shows the basic architecture of each PWM. PWM
functionality is split into two major parts, a APB domain and a PWM domain, both of which
run on clocks derived from the BASE_MSCSS_CLK. This split into two domains affects
behavior from a system-level perspective. The actual PWM and prescale counters are
located in the PWM domain but system control takes place in the APB domain.
The actual PWM consists of two counters; a 16-bit prescale counter and a 16-bit PWM
counter. The position of the rising and falling edges of the PWM outputs can be
programmed individually. The prescale counter allows high system bus frequencies to be
scaled down to lower PWM periods. Registers are available to capture the PWM counter
values on external events.
Note that in the Modulation and Sampling Control SubSystem (MSCSS), each PWM has
its individual clock source CLK_MSCSS_PWMx (x runs from 0 to 3). Both the prescale
and the timer counters within each PWM run on this clock CLK_MSCSS_PWMx, and all
time references are related to the period of this clock. See Section 6.15 for information on
generation of these clocks.
6.14.5.2
Synchronizing the PWM counters
A mechanism is included to synchronize the PWM period to other PWMs by providing a
sync input and a sync output with programmable delay. Several PWMs can be
synchronized using the trans_enable_in/trans_enable_out and sync_in/sync_out ports.
See Figure 5 for details of the connections of the PWM modules within the MSCSS in the
LPC2921/2923/2925. PWM0 can be master over PWM1; PWM1 can be master over
PWM2, etc.
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6.14.5.3
Master and slave mode
A PWM module can provide synchronization signals to other modules (also called Master
mode). The signal sync_out is a pulse of one clock cycle generated when the internal
PWM counter (re)starts. The signal trans_enable_out is a pulse synchronous to sync_out,
generated if a transfer from system registers to PWM shadow registers occurred when the
PWM counter restarted. A delay may be inserted between the counter start and
generation of trans_enable_out and sync_out.
A PWM module can use input signals trans_enable_in and sync_in to synchronize its
internal PWM counter and the transfer of shadow registers (Slave mode).
6.14.5.4
Pin description
Each of the four PWM modules in the MSCSS has the following pins. These are combined
with other functions on the port pins of the LPC2921/2923/2925. Table 21 shows the
PWM0 to PWM3 pins (n = 0 to 3).
Table 21.
6.14.5.5
PWM pins
Symbol
Pin name
Direction
Description
PWMn CAP[0]
PCAPn[0]
IN
PWMn capture input 0
PWMn CAP[1]
PCAPn[1]
IN
PWMn capture input 1
PWMn CAP[2]
PCAPn[2]
IN
PWMn capture input 2
PWMn MAT[0]
PMATn[0]
OUT
PWMn match output 0
PWMn MAT[1]
PMATn[1]
OUT
PWMn match output 1
PWMn MAT[2]
PMATn[2]
OUT
PWMn match output 2
PWMn MAT[3]
PMATn[3]
OUT
PWMn match output 3
PWMn MAT[4]
PMATn[4]
OUT
PWMn match output 4
PWMn MAT[5]
PMATn[5]
OUT
PWMn match output 5
PWMn TRAP
TRAPn
IN
PWMn trap input (on the LPC2921/2923/2925
n = 2, 3)
Clock description
The PWM modules are clocked by CLK_MSCSS_PWMx (x = 0 to 3), see Section 6.7.2.
Note that each PWM has its own CLK_MSCSS_PWMx branch clock for power
management. The frequency of all these clocks is identical to CLK_MSCSS_APB since
they are derived from the same base clock BASE_MSCSS_CLK.
Also note that unlike the timer modules in the Peripheral SubSystem, the actual timer
counter registers of the PWM modules run at the same clock as the APB system interface
CLK_MSCSS_APB. This clock is independent of the AHB system clock.
If a PWM module is not used its CLK_MSCSS_PWMx branch clock can be switched off.
6.14.6 Timers in the MSCSS
The two timers in the MSCSS are functionally identical to the timers in the peripheral
subsystem, see Section 6.12.3. The features of the timers in the MSCSS are the same as
the timers in the peripheral subsystem, but the capture inputs and match outputs are not
available on the device pins. These signals are instead connected to the ADC and PWM
modules as outlined in the description of the MSCSS, see Section 6.14.1.
See Section 6.12.3 for a functional description of the timers.
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6.14.6.1
Pin description
MSCSS timer 0 has no external pins.
MSCSS timer 1 has a PAUSE pin available as external pin. The PAUSE pin is combined
with other functions on the port pins of the LPC2921/2923/2925. Table 22 shows the
MSCSS timer 1 external pin.
Table 22.
6.14.6.2
MSCSS timer 1 pin
Symbol
Direction
Description
MSCSS PAUSE
IN
pause pin for MSCSS timer 1
Clock description
The timer modules in the MSCSS are clocked by CLK_MSCSS_MTMRx (x = 0 to 1), see
Section 6.7.2. Note that each timer has its own CLK_MSCSS_MTMRx branch clock for
power management. The frequency of all these clocks is identical to CLK_MSCSS_APB
since they are derived from the same base clock BASE_MSCSS_CLK.
Note that, unlike the timer modules in the Peripheral SubSystem, the actual timer counter
registers run at the same clock as the APB system interface CLK_MSCSS_APB. This
clock is independent of the AHB system clock.
If a timer module is not used its CLK_MSCSS_MTMRx branch clock can be switched off.
6.14.7 Quadrature Encoder Interface (QEI)
A quadrature encoder, also known as a 2-channel incremental encoder, converts angular
displacement into two pulse signals. By monitoring both the number of pulses and the
relative phase of the two signals, the user can track the position, direction of rotation, and
velocity. In addition, a third channel, or index signal, can be used to reset the position
counter. The quadrature encoder interface decodes the digital pulses from a quadrature
encoder wheel to integrate position over time and determine direction of rotation. In
addition, the QEI can capture the velocity of the encoder wheel.
The QEI has the following features:
•
•
•
•
•
•
•
•
•
•
Tracks encoder position.
Increments/decrements depending on direction.
Programmable for 2× or 4× position counting.
Velocity capture using built-in timer.
Velocity compare function with less than interrupt.
Uses 32-bit registers for position and velocity.
Three position compare registers with interrupts.
Index counter for revolution counting.
Index compare register with interrupts.
Can combine index and position interrupts to produce an interrupt for whole and
partial revolution displacement.
• Digital filter with programmable delays for encoder input signals.
• Can accept decoded signal inputs (clk and direction).
• Connected to APB.
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6.14.7.1
Pin description
The QEI module in the MSCSS has the following pins. These are combined with other
functions on the port pins of the LPC2921/2923/2925. Table 23 shows the QEI pins.
Table 23.
QEI pins
Symbol
Pin name
Direction
Description
QEI0 PHA
PHA0
IN
Sensor signal. Corresponds to PHA in
quadrature mode and to direction in
clock/direction mode.
QEI0 PHB
PHB0
IN
Sensor signal. Corresponds to PHB in
quadrature mode and to clock signal in
clock/direction mode.
Remark: The index function for the QEI is not pinned out on the LPC2921/2923/2925.
6.14.7.2
Clock description
The QEI module is clocked by CLK_MSCSS_QEI, see Section 6.7.2. The frequency of
this clock is identical to CLK_MSCSS_APB since they are derived from the same base
clock BASE_MSCSS_CLK.
If the QEI is not used its CLK_MSCSS_QEI branch clock can be switched off.
6.15 Power, Clock, and Reset control SubSystem (PCRSS)
The Power, Clock, and Reset control SubSystem (PCRSS) in the LPC2921/2923/2925
includes a Clock Generator Unit (CGU), a Reset Generator Unit (RGU) and a Power
Management Unit (PMU).
Figure 8 provides an overview of the PCRSS. An AHB-to-DTL bridge controls the
communication with the AHB system bus.
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CGU0
PMU
CGU1
PLL
EXTERNAL
OSCILLATOR
OUT6
OUT11
OUT0
PLL
OUT2
OUT0
OUT1
LOW POWER
RING
OSCILLATOR
FDIV[6:0]
branch
clocks
CLOCK
GATES
FDIV
OUT5
OUT7
OUT9
CGU0
REGISTERS
CLOCK
ENABLE
CONTROL
PMU
REGISTERS
AHB2DTL
BRIDGE
AHB
master
disable:
grant
request
wakeup_a
RGU
AHB_RST
RGU
REGISTERS
SCU_RST
RESET OUTPUT
DELAY LOGIC
POR
WARM_RST
COLD_RST
PCR_RST
RGU_RST
POR_RST
INPUT
DEGLITCH/
SYNC
reset from watchdog counter
RST (device pin)
002aae249
Fig 8.
Power, Clock, and Reset control SubSystem (PCRSS) block diagram
6.15.1 Clock description
The PCRSS is clocked by a number of different clocks. CLK_SYS_PCRSS clocks the
AHB side of the AHB to DTL bus bridge and CLK_PCR_SLOW clocks the CGU, RGU and
PMU internal logic, see Section 6.7.2. CLK_SYS_PCRSS is derived from
BASE_SYS_CLK, which can be switched off in low-power modes. CLK_PCR_SLOW is
derived from BASE_PCR_CLK and is always on in order to be able to wake up from
low-power modes.
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6.15.2 Clock Generation Unit (CGU0)
The key features are:
•
•
•
•
•
•
•
•
•
•
Generation of 11 base clocks selectable from several embedded clock sources.
Crystal oscillator with power-down.
Control PLL with power-down.
Very low-power ring oscillator, always on to provide a safe clock.
Seven fractional clock dividers with L/D division.
Individual source selector for each base clock, with glitch-free switching.
Autonomous clock-activity detection on every clock source.
Protection against switching to invalid or inactive clock sources.
Embedded frequency counter.
Register write-protection mechanism to prevent unintentional alteration of clocks.
Remark: Any clock-frequency adjustment has a direct impact on the timing of all on-board
peripherals.
6.15.2.1
Functional description
The clock generation unit provides 11 internal clock sources as described in Table 24.
Table 24.
CGU0 base clocks
Number Name
Frequency
(MHz) [1]
Description
0
0.4
base safe clock (always on)
BASE_SAFE_CLK
1
BASE_SYS_CLK
125
base system clock
2
BASE_PCR_CLK
0.4 [2]
base PCR subsystem clock
3
BASE_IVNSS_CLK
125
base IVNSS subsystem clock
4
BASE_MSCSS_CLK
125
base MSCSS subsystem clock
5
BASE_ICLK0_CLK
125
base internal clock 0, for CGU1
6
BASE_UART_CLK
125
base UART clock
7
BASE_SPI_CLK
50
base SPI clock
8
BASE_TMR_CLK
125
base timers clock
9
BASE_ADC_CLK
4.5
base ADCs clock
10
reserved
-
-
11
BASE_ICLK1_CLK
125
base internal clock 1, for CGU1
[1]
Maximum frequency that guarantees stable operation of the LPC2921/2923/2925.
[2]
Fixed to low-power oscillator.
For generation of these base clocks, the CGU consists of primary and secondary clock
generators and one output generator for each base clock.
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CLOCK GENERATION UNIT (CGU0)
OUT 0
BASE_SAFE_CLK
OUT 1
BASE_SYS_CLK
OUT 2
BASE_PCR_CLK
OUT 3
BASE_IVNSS_CLK
OUT 11
BASE_ICLK1_CLK
FDIV0
400 kHz LP_OSC
EXTERNAL
OSCILLATOR
PLL
clkout
clkout120
clkout240
FDIV1
FDIV6
FREQUENCY
MONITOR
CLOCK
DETECTION
AHB TO DTL BRIDGE
002aae147
Fig 9.
Block diagram of the CGU0 (see Table 24 for all base clocks)
There are two primary clock generators: a low-power ring oscillator (LP_OSC) and a
crystal oscillator. See Figure 9.
LP_OSC is the source for the BASE_PCR_CLK that clocks the CGU itself and for
BASE_SAFE_CLK that clocks a minimum of other logic in the device (like the watchdog
timer). To prevent the device from losing its clock source LP_OSC cannot be put into
power-down. The crystal oscillator can be used as source for high-frequency clocks or as
an external clock input if a crystal is not connected.
Secondary clock generators are a PLL and seven fractional dividers (FDIV[0:6]). The PLL
has three clock outputs: normal, 120° phase-shifted and 240° phase-shifted.
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Configuration of the CGU0: For every output generator generating the base clocks a
choice can be made from the primary and secondary clock generators according to
Figure 10.
LP_OSC
FDIV0:6
EXTERNAL
OSCILLATOR
PLL
clkout
clkout120
clkout240
OUTPUT
CONTROL
clock
outputs
002aad834
Fig 10. Structure of the clock generation scheme
Any output generator (except for BASE_SAFE_CLK and BASE_PCR_CLK) can be
connected to either a fractional divider (FDIV[0:6]) or to one of the outputs of the PLL or to
LP_OSC/crystal oscillator directly. BASE_SAFE_CLK and BASE_PCR_CLK can use only
LP_OSC as source.
The fractional dividers can be connected to one of the outputs of the PLL or directly to
LP_OSC/crystal Oscillator.
The PLL is connected to the crystal oscillator.
In this way every output generating the base clocks can be configured to get the required
clock. Multiple output generators can be connected to the same primary or secondary
clock source, and multiple secondary clock sources can be connected to the same PLL
output or primary clock source.
Invalid selections/programming - connecting the PLL to an FDIV or to one of the PLL
outputs itself for example - will be blocked by hardware. The control register will not be
written, the previous value will be kept, although all other fields will be written with new
data. This prevents clocks being blocked by incorrect programming.
Default Clock Sources: Every secondary clock generator or output generator is
connected to LP_OSC at reset. In this way the device runs at a low frequency after reset.
It is recommended to switch BASE_SYS_CLK to a high-frequency clock generator as
(one of) the first step(s) in the boot code after verifying that the high-frequency clock
generator is running.
Clock Activity Detection: Clocks that are inactive are automatically regarded as invalid,
and values of ‘CLK_SEL’ that would select those clocks are masked and not written to the
control registers. This is accomplished by adding a clock detector to every clock
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generator. The RDET register keeps track of which clocks are active and inactive, and the
appropriate ‘CLK_SEL’ values are masked and unmasked accordingly. Each clock
detector can also generate interrupts at clock activation and deactivation so that the
system can be notified of a change in internal clock status.
Clock detection is done using a counter running at the BASE_PCR_CLK frequency. If no
positive clock edge occurs before the counter has 32 cycles of BASE_PCR_CLK the clock
is assumed to be inactive. As BASE_PCR_CLK is slower than any of the clocks to be
detected, normally only one BASE_PCR_CLK cycle is needed to detect activity. After
reset all clocks are assumed to be ‘non-present’, so the RDET status register will be
correct only after 32 BASE_PCR_CLK cycles.
Note that this mechanism cannot protect against a currently-selected clock going from
active to inactive state. Therefore an inactive clock may still be sent to the system under
special circumstances, although an interrupt can still be generated to notify the system.
Glitch-Free Switching: Provisions are included in the CGU to allow clocks to be
switched glitch-free, both at the output generator stage and also at secondary source
generators.
In the case of the PLL the clock will be stopped and held low for long enough to allow the
PLL to stabilize and lock before being re-enabled. For all non-PLL Generators the switch
will occur as quickly as possible, although there will always be a period when the clock is
held low due to synchronization requirements.
If the current clock is high and does not go low within 32 cycles of BASE_PCR_CLK it is
assumed to be inactive and is asynchronously forced low. This prevents deadlocks on the
interface.
6.15.2.2
PLL functional description
A block diagram of the PLL is shown in Figure 11. The input clock is fed directly to the
analog section. This block compares the phase and frequency of the inputs and generates
the main clock2. These clocks are either divided by 2 × P by the programmable post
divider to create the output clock, or sent directly to the output. The main output clock is
then divided by M by the programmable feedback divider to generate the feedback clock.
The output signal of the analog section is also monitored by the lock detector to signal
when the PLL has locked onto the input clock.
2.
Generation of the main clock is restricted by the frequency range of the PLL clock input. See Table 33 “Dynamic characteristics”.
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PSEL bits
P23EN bit
input clock
/ 2PDIV
P23
CCO
clkout120
clkout240
clkout
bypass
direct
/ MDIV
clkout
002aad833
MSEL bits
Fig 11. PLL block diagram
Triple output phases: For applications that require multiple clock phases two additional
clock outputs can be enabled by setting register P23EN to logic 1, thus giving three clocks
with a 120° phase difference. In this mode all three clocks generated by the analog
section are sent to the output dividers. When the PLL has not yet achieved lock the
second and third phase output dividers run unsynchronized, which means that the phase
relation of the output clocks is unknown. When the PLL LOCK register is set the second
and third phase of the output dividers are synchronized to the main output clock CLKOUT
PLL, thus giving three clocks with a 120° phase difference.
Direct output mode: In normal operating mode (with DIRECT set to logic 0) the CCO
clock is divided by 2, 4, 8 or 16 depending on the value on the PSEL[1:0] input, giving an
output clock with a 50 % duty cycle. If a higher output frequency is needed the CCO clock
can be sent directly to the output by setting DIRECT to logic 1. Since the CCO does not
directly generate a 50 % duty cycle clock, the output clock duty cycle in this mode can
deviate from 50 %.
Power-down control: A Power-down mode has been incorporated to reduce power
consumption when the PLL clock is not needed. This is enabled by setting the PD control
register bit. In this mode the analog section of the PLL is turned off, the oscillator and the
phase-frequency detector are stopped and the dividers enter a reset state. While in
Power-down mode the LOCK output is low, indicating that the PLL is not in lock. When
Power-down mode is terminated by clearing the PD control-register bit the PLL resumes
normal operation, and makes the LOCK signal high once it has regained lock on the input
clock.
6.15.2.3
Pin description
The CGU0 module in the LPC2921/2923/2925 has the pins listed in Table 25 below.
Table 25.
LPC2921_23_25_3
Product data sheet
CGU0 pins
Symbol
Direction
Description
XOUT_OSC
OUT
Oscillator crystal output
XIN_OSC
IN
Oscillator crystal input or external clock input
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6.15.3 Clock generation for USB (CGU1)
The CGU1 block is functionally identical to the CGU0 block and generates the clock for
the USB interface and a dedicated output clock. The CGU1 block uses its own PLL and
fractional divider. The PLLs used in CGU0 and CGU1 are identical (see Section 6.15.2.2).
The clock input to the CGU1 PLL is provided by one of two base clocks generated in the
CGU0: BASE_ICLK0_CLK or BASE_ICLK1_CLK. The base clock not used for the PLL
can be configured to drive the output clock directly.
CLOCK GENERATION UNIT
(CGU1)
BASE_ICLK0_CLK
BASE_ICLK1_CLK
PLL
clkout
clkout120
clkout240
OUT 0
BASE_USB_CLK
OUT 2
BASE_OUT_CLK
FDIV0
AHB TO DTL BRIDGE
002aae250
Fig 12. Block diagram of the CGU1
6.15.3.1
Pin description
The CGU1 module in the LPC2921/2923/2925 has the pins listed in Table 25 below.
Table 26.
CGU1 pins
Symbol
Direction
Description
CLK_OUT
OUT
clock output
6.15.4 Reset Generation Unit (RGU)
The RGU controls all internal resets.
The key features of the Reset Generation Unit (RGU) are:
• Reset controlled individually per subsystem
• Automatic reset stretching and release
• Monitor function to trace resets back to source
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• Register write-protection mechanism to prevent unintentional resets
6.15.4.1
Functional description
Each reset output is defined as a combination of reset input sources including the external
reset input pins and internal power-on reset, see Table 27. The first five resets listed in
this table form a sort of cascade to provide the multiple levels of impact that a reset may
have. The combined input sources are logically OR-ed together so that activating any of
the listed reset sources causes the output to go active.
Table 27.
6.15.4.2
Reset output configuration
Reset output
Reset source
Parts of the device reset when activated
POR_RST
power-on reset module
LP_OSC; source for RGU_RST
RGU_RST
POR_RST, RST_N pin
RGU internal; source for PCR_RST
PCR_RST
RGU_RST, WATCHDOG PCR internal; source for COLD_RST
COLD_RST
PCR_RST
parts with COLD_RST as reset source below
WARM_RST
COLD_RST
parts with WARM_RST as reset source below
SCU_RST
COLD_RST
SCU
CFID_RST
COLD_RST
CFID
FMC_RST
COLD_RST
embedded Flash Memory Controller (FMC)
EMC_RST
COLD_RST
embedded SRAM-Memory Controller
GESS_A2V_RST
WARM_RST
GeSS AHB-to-APB bridge
PESS_A2V_RST
WARM_RST
PeSS AHB-to-APB bridge
GPIO_RST
WARM_RST
all GPIO modules
UART_RST
WARM_RST
all UART modules
TMR_RST
WARM_RST
all timer modules in PeSS
SPI_RST
WARM_RST
all SPI modules
IVNSS_A2V_RST
WARM_RST
IVNSS AHB-to-APB bridge
IVNSS_CAN_RST
WARM_RST
all CAN modules including Acceptance filter
IVNSS_LIN_RST
WARM_RST
all LIN modules
MSCSS_A2V_RST
WARM_RST
MSCSS AHB to APB bridge
MSCSS_PWM_RST
WARM_RST
all PWM modules
MSCSS_ADC_RST
WARM_RST
all ADC modules
MSCSS_TMR_RST
WARM_RST
all timer modules in MSCSS
I2C_RST
WARM_RST
all I2C modules
QEI_RST
WARM_RST
Quadrature encoder
DMA_RST
WARM_RST
DMA controller
USB_RST
WARM_RST
USB controller
VIC_RST
WARM_RST
Vectored Interrupt Controller (VIC)
AHB_RST
WARM_RST
CPU and AHB Bus infrastructure
Pin description
The RGU module in the LPC2921/2923/2925 has the following pins. Table 28 shows the
RGU pins.
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Table 28.
RGU pins
Symbol
Direction
Description
RST
IN
external reset input, active LOW; pulled up internally
6.15.5 Power Management Unit (PMU)
This module enables software to actively control the system’s power consumption by
disabling clocks not required in a particular operating mode.
Using the base clocks from the CGU as input, the PMU generates branch clocks to the
rest of the LPC2921/2923/2925. Output clocks branched from the same base clock are
phase- and frequency-related. These branch clocks can be individually controlled by
software programming.
The key features are:
•
•
•
•
•
•
•
6.15.5.1
Individual clock control for all LPC2921/2923/2925 sub-modules.
Activates sleeping clocks when a wake-up event is detected.
Clocks can be individually disabled by software.
Supports AHB master-disable protocol when AUTO mode is set.
Disables wake-up of enabled clocks when Power-down mode is set.
Activates wake-up of enabled clocks when a wake-up event is received.
Status register is available to indicate if an input base clock can be safely switched off
(i.e. all branch clocks are disabled).
Functional description
The PMU controls all internal clocks coming out of the CGU0 for power-mode
management. With some exceptions, each branch clock can be switched on or off
individually under control of software register bits located in its individual configuration
register. Some branch clocks controlling vital parts of the device operate in a fixed mode.
Table 29 shows which mode-control bits are supported by each branch clock.
By programming the configuration register the user can control which clocks are switched
on or off, and which clocks are switched off when entering Power-down mode.
Note that the standby-wait-for-interrupt instructions of the ARM968E-S processor (putting
the ARM CPU into a low-power state) are not supported. Instead putting the ARM CPU
into power-down should be controlled by disabling the branch clock for the CPU.
Remark: For any disabled branch clocks to be re-activated their corresponding base
clocks must be running (controlled by the CGU0).
Table 29 shows the relation between branch and base clocks, see also Section 6.7.1.
Every branch clock is related to one particular base clock: it is not possible to switch the
source of a branch clock in the PMU.
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Table 29. Branch clock overview
Legend:
‘1’ Indicates that the related register bit is tied off to logic HIGH, all writes are ignored
‘0’ Indicates that the related register bit is tied off to logic LOW, all writes are ignored
‘+’ Indicates that the related register bit is readable and writable
LPC2921_23_25_3
Product data sheet
Branch clock name
Base clock
Implemented switch on/off
mechanism
WAKE-UP
AUTO
RUN
CLK_SAFE
BASE_SAFE_CLK
0
0
1
CLK_SYS_CPU
BASE_SYS_CLK
+
+
1
CLK_SYS
BASE_SYS_CLK
+
+
1
CLK_SYS_PCR
BASE_SYS_CLK
+
+
1
CLK_SYS_FMC
BASE_SYS_CLK
+
+
+
CLK_SYS_RAM0
BASE_SYS_CLK
+
+
+
CLK_SYS_RAM1
BASE_SYS_CLK
+
+
+
CLK_SYS_GESS
BASE_SYS_CLK
+
+
+
CLK_SYS_VIC
BASE_SYS_CLK
+
+
+
CLK_SYS_PESS
BASE_SYS_CLK
+
+
+
CLK_SYS_GPIO0
BASE_SYS_CLK
+
+
+
CLK_SYS_GPIO1
BASE_SYS_CLK
+
+
+
CLK_SYS_GPIO5
BASE_SYS_CLK
+
+
+
CLK_SYS_IVNSS_A
BASE_SYS_CLK
+
+
+
CLK_SYS_MSCSS_A
BASE_SYS_CLK
+
+
+
CLK_SYS_DMA
BASE_SYS_CLK
+
+
+
CLK_SYS_USB
BASE_SYS_CLK
+
+
+
CLK_PCR_SLOW
BASE_PCR_CLK
+
+
1
CLK_IVNSS_APB
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_CANC0
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_CANC1
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_I2C0
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_I2C1
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_LIN0
BASE_IVNSS_CLK
+
+
+
CLK_IVNSS_LIN1
BASE_IVNSS_CLK
+
+
+
CLK_MSCSS_APB
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_MTMR0
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_MTMR1
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_PWM0
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_PWM1
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_PWM2
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_PWM3
BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_ADC1_APB BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_ADC2_APB BASE_MSCSS_CLK
+
+
+
CLK_MSCSS_QEI
BASE_MSCSS_CLK
+
+
+
CLK_OUT_CLK
BASE_OUT_CLK
+
+
+
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Table 29. Branch clock overview …continued
Legend:
‘1’ Indicates that the related register bit is tied off to logic HIGH, all writes are ignored
‘0’ Indicates that the related register bit is tied off to logic LOW, all writes are ignored
‘+’ Indicates that the related register bit is readable and writable
Branch clock name
Base clock
Implemented switch on/off
mechanism
WAKE-UP
AUTO
RUN
CLK_UART0
BASE_UART_CLK
+
+
+
CLK_UART1
BASE_UART_CLK
+
+
+
CLK_SPI0
BASE_SPI_CLK
+
+
+
CLK_SPI1
BASE_SPI_CLK
+
+
+
CLK_SPI2
BASE_SPI_CLK
+
+
+
CLK_TMR0
BASE_TMR_CLK
+
+
+
CLK_TMR1
BASE_TMR_CLK
+
+
+
CLK_TMR2
BASE_TMR_CLK
+
+
+
CLK_TMR3
BASE_TMR_CLK
+
+
+
CLK_ADC1
BASE_ADC_CLK
+
+
+
CLK_ADC2
BASE_ADC_CLK
+
+
+
CLK_USB
BASE_USB_CLK
+
+
+
6.16 Vectored interrupt controller
The LPC2921/2923/2925 contains a very flexible and powerful Vectored Interrupt
Controller (VIC) to interrupt the ARM processor on request.
The key features are:
•
•
•
•
•
•
Level-active interrupt request with programmable polarity.
56 interrupt-request inputs.
Software-interrupt request capability associated with each request input.
Interrupt request state can be observed before masking.
Software-programmable priority assignments to interrupt requests up to 15 levels.
Software-programmable routing of interrupt requests towards the ARM-processor
inputs IRQ and FIQ.
• Fast identification of interrupt requests through vector.
• Support for nesting of interrupt service routines.
6.16.1 Functional description
The Vectored Interrupt Controller routes incoming interrupt requests to the ARM
processor. The interrupt target is configured for each interrupt request input of the VIC.
The targets are defined as follows:
• Target 0 is ARM processor FIQ (fast interrupt service).
• Target 1 is ARM processor IRQ (standard interrupt service).
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Interrupt-request masking is performed individually per interrupt target by comparing the
priority level assigned to a specific interrupt request with a target-specific priority
threshold. The priority levels are defined as follows:
• Priority level 0 corresponds to ‘masked’ (i.e. interrupt requests with priority 0 never
lead to an interrupt).
• Priority 1 corresponds to the lowest priority.
• Priority 15 corresponds to the highest priority.
Software interrupt support is provided and can be supplied for:
• Testing RTOS (Real-Time Operating System) interrupt handling without using
device-specific interrupt service routines.
• Software emulation of an interrupt-requesting device, including interrupts.
6.16.2 Clock description
The VIC is clocked by CLK_SYS_VIC, see Section 6.7.2.
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7. Limiting values
Table 30. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
Conditions
Min
Max
Unit
Supply pins
[1]
Ptot
total power dissipation
-
1.5
W
VDD(CORE)
core supply voltage
−0.5
+2.0
V
VDD(OSC_PLL)
oscillator and PLL supply
voltage
−0.5
+2.0
V
VDDA(ADC3V3)
3.3 V ADC analog supply
voltage
−0.5
+4.6
V
VDD(IO)
input/output supply voltage
IDD
supply current
average value per supply
pin
[2]
ISS
ground current
average value per ground
pin
[2]
−0.5
+4.6
V
-
98
mA
-
98
mA
Input pins and I/O pins
VXIN_OSC
voltage on pin XIN_OSC
VI(IO)
I/O input voltage
+2.0
V
−0.5
VDD(IO) + 3.0
V
[4][5]
−0.5
VDDA(ADC3V3)
+ 0.5
V
VI(ADC)
ADC input voltage
VVREFP
voltage on pin VREFP
−0.5
+3.6
V
VVREFN
voltage on pin VREFN
−0.5
+3.6
V
[2]
-
35
mA
II(ADC)
ADC input current
for ADC1/2: I/O port 0 pin 8
to pin 23.
−0.5
[3][4][5]
average value per input pin
Output pins and I/O pins configured as output
IOHS
HIGH-level short-circuit
output current
drive HIGH, output shorted
to VSS(IO)
[6]
-
−33
mA
IOLS
LOW-level short-circuit
output current
drive LOW, output shorted
to VDD(IO)
[6]
-
+38
mA
General
Tstg
storage temperature
−65
+150
°C
Tamb
ambient temperature
−40
+85
°C
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Table 30. Limiting values …continued
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
Conditions
electrostatic discharge
voltage
on all pins
Min
Max
Unit
−2000
+2000
V
−500
+500
V
−750
+750
V
ESD
VESD
human body model
charged device model
[7]
on corner pins
charged device model
[1]
Based on package heat transfer, not device power consumption.
[2]
Peak current must be limited at 25 times average current.
[3]
For I/O Port 0, the maximum input voltage is defined by VI(ADC).
[4]
Only when VDD(IO) is present.
[5]
Note that pull-up should be off. With pull-up do not exceed 3.6 V.
[6]
112 mA per VDD(IO) or VSS(IO) should not be exceeded.
[7]
Human-body model: discharging a 100 pF capacitor via a 10 kΩ series resistor.
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8. Static characteristics
Table 31. Static characteristics
VDD(CORE) = VDD(OSC_PLL) ; VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; Tvj = −40 °C to +85 °C; all voltages are
measured with respect to ground; positive currents flow into the IC; unless otherwise specified.[1]
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
1.71
1.80
1.89
V
-
75
-
mA
-
30
475
μA
2.7
-
3.6
V
-
0.5
3.25
μA
1.71
1.80
1.89
V
Supplies
Core supply
VDD(CORE)
core supply voltage
IDD(CORE)
core supply current
Device state after reset;
system clock at
125 MHz; Tamb = 85 °C;
executing code
while(1){} from flash.
all clocks off
[2]
I/O supply
VDD(IO)
input/output supply
voltage
IDD(IO)
I/O supply current
Power-down mode
Oscillator/PLL supply
VDD(OSC_PLL)
oscillator and PLL supply
voltage
IDD(OSC_PLL)
oscillator and PLL supply
current
Normal mode
-
-
1
mA
Power-down mode
-
-
2
μA
3.0
3.3
3.6
V
Normal mode
-
-
1.9
mA
Power-down mode
-
-
4
μA
−0.5
-
+ 5.5
V
-
-
VVREFP
all port pins and VDD(IO)
not applied
−0.5
-
+3.6
V
all other I/O pins, RST,
TRST, TDI, JTAGSEL,
TMS, TCK
−0.5
-
VDD(IO)
V
Analog-to-digital converter supply
VDDA(ADC3V3)
3.3 V ADC analog supply
voltage
IDDA(ADC3V3)
3.3 V ADC analog supply
current
Input pins and I/O pins configured as input
VI
input voltage
all port pins and VDD(IO)
applied;
[3][4]
see Section 7
port 0 pin 8 to pin 23
when ADC1/2 is used
[4]
VIH
HIGH-level input voltage
all port pins, RST, TRST,
TDI, JTAGSEL, TMS,
TCK
2.0
-
-
V
VIL
LOW-level input voltage
all port pins, RST, TRST,
TDI, JTAGSEL, TMS,
TCK
-
-
0.8
V
Vhys
hysteresis voltage
0.4
-
-
V
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Table 31. Static characteristics …continued
VDD(CORE) = VDD(OSC_PLL) ; VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; Tvj = −40 °C to +85 °C; all voltages are
measured with respect to ground; positive currents flow into the IC; unless otherwise specified.[1]
Symbol
Parameter
ILIH
Conditions
Min
Typ
Max
Unit
HIGH-level input leakage
current
-
-
1
μA
ILIL
LOW-level input leakage
current
-
-
1
μA
II(pd)
pull-down input current
all port pins, VI = 3.3 V;
VI = 5.5 V; see Figure 20
25
50
100
μA
II(pu)
pull-up input current
all port pins, RST, TRST,
TDI, JTAGSEL, TMS:
VI = 0 V; VI > 3.6 V is not
allowed; Figure 21
−25
−50
−115
μA
Ci
input capacitance
-
3
8
pF
[5]
Output pins and I/O pins configured as output
VO
output voltage
0
-
VDD(IO)
V
VOH
HIGH-level output voltage IOH = −4 mA; see
Figure 19
VDD(IO) − 0.4
-
-
V
VOL
LOW-level output voltage
-
-
0.4
V
CL
load capacitance
-
-
25
pF
IOL = 4 mA; Figure 18
USB pins USB_D+ and USB_D−
Input characteristics
VIH
HIGH-level input voltage
1.5
-
-
V
VIL
LOW-level input voltage
-
-
1.3
V
Vhys
hysteresis voltage
0.4
-
-
V
36.0
-
44.1
Ω
Output characteristics
with 33 Ω series resistor
Zo
output impedance
VOH
HIGH-level output voltage (driven) for
low-/full-speed; RL of
15 kΩ to GND
2.9
-
3.5
V
VOL
LOW-level output voltage
-
-
0.18
V
IOH
HIGH-level output current at VOH = VDD(IO) − 0.3 V;
without 33 Ω external
series resistor
20.8
-
41.7
mA
at VOH = VDD(IO) − 0.3 V;
with 33 Ω external series
resistor
4.8
-
5.3
mA
at VOL = 0.3 V; without
33 Ω external series
resistor
26.7
-
57.2
mA
at VOL = 0.3 V; with 33 Ω
external series resistor
5.0
-
5.5
mA
drive high; pad
connected to ground
-
-
90.0
mA
IOL
IOHS
LOW-level output current
HIGH-level short-circuit
output current
LPC2921_23_25_3
Product data sheet
(driven) for
low-/full-speed; with
1.5 kΩ resistor to 3.6 V
external pull-up
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Table 31. Static characteristics …continued
VDD(CORE) = VDD(OSC_PLL) ; VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; Tvj = −40 °C to +85 °C; all voltages are
measured with respect to ground; positive currents flow into the IC; unless otherwise specified.[1]
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
IOLS
LOW-level short-circuit
output current
drive high; pad
connected to VDD(IO)
-
-
95.1
mA
0
-
1.8
V
Cxtal = 10 pF;
Cext = 18 pF
-
-
160
Ω
Cxtal = 20 pF;
Cext = 39 pF
-
-
60
Ω
-
-
80
Ω
[7]
-
-
2
pF
high trip level voltage
[8]
1.1
1.4
1.6
V
low trip level voltage
[8]
1.0
1.3
1.5
V
difference between high
and low trip level voltage
[8]
50
120
180
mV
Oscillator
VXIN_OSC
Rs(xtal)
voltage on pin XIN_OSC
crystal series resistance
fosc = 10 MHz to 15 MHz
fosc = 15 MHz to 20 MHz
[6]
[6]
Cxtal = 10 pF;
Cext = 18 pF
input capacitance
Ci
of XIN_OSC
Power-up reset
Vtrip(high)
Vtrip(low)
Vtrip(dif)
[1]
All parameters are guaranteed over the virtual junction temperature range by design. Pre-testing is performed at Tamb = 85 °C on wafer
level. Cased products are tested at Tamb = 25 °C (final testing). Both pre-testing and final testing use correlated test conditions to cover
the specified temperature and power-supply voltage range.
[2]
Leakage current is exponential to temperature; worst-case value is at 85 °C Tvj. All clocks off. Analog modules and flash powered down.
[3]
Not 5 V-tolerant when pull-up is on.
[4]
For I/O Port 0, the maximum input voltage is defined by VI(ADC).
[5]
For Port 0, pin 0 to pin 15 add maximum 1.5 pF for input capacitance to ADC. For Port 0, pin 16 to pin 31 add maximum 1.0 pF for input
capacitance to ADC.
[6]
Cxtal is crystal load capacitance and Cext are the two external load capacitors.
[7]
This parameter is not part of production testing or final testing, hence only a typical value is stated. Maximum and minimum values are
based on simulation results.
[8]
The power-up reset has a time filter: VDD(CORE) must be above Vtrip(high) for 2 μs before reset is de-asserted; VDD(CORE) must be below
Vtrip(low) for 11 μs before internal reset is asserted.
LPC2921_23_25_3
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Table 32. ADC static characteristics
VDDA(ADC3V3) = 3.0 V to 3.6 V; Tamb = −40 °C to +85 °C unless otherwise specified; ADC frequency 4.5 MHz.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
-
VVREFN
voltage on pin VREFN
0
VVREFP − 2
V
VVREFP
voltage on pin VREFP
VVREFN + 2 -
VDDA(ADC3V3)
V
VIA
analog input voltage
VVREFN
-
VVREFP
V
Zi
input impedance
4.4
-
-
kΩ
Cia
analog input capacitance
between VVREFN and
VVREFP
-
-
1
pF
[1][2][3]
-
-
±1
LSB
integral non-linearity
[1][4]
-
-
±2
LSB
EO
offset error
[1][5]
-
-
±3
LSB
EG
gain error
[1][6]
-
-
±0.5
%
absolute error
[1][7]
-
-
±4
LSB
[8]
-
-
40
kΩ
2
-
10
bit
differential linearity error
ED
EL(adj)
ET
Rvsi
voltage source interface
resistance
FSR
full scale range
[1]
Conditions: VSS(IO) = 0 V, VDDA(ADC3V3) = 3.3 V.
[2]
The ADC is monotonic, there are no missing codes.
[3]
The differential linearity error (ED) is the difference between the actual step width and the ideal step width. See Figure 14.
[4]
The integral non-linearity (EL(adj)) is the peak difference between the center of the steps of the actual and the ideal transfer curve after
appropriate adjustment of gain and offset errors. See Figure 14.
[5]
The offset error (EO) is the absolute difference between the straight line which fits the actual curve and the straight line which fits the
ideal curve. See Figure 14.
[6]
The gain error (EG) is the relative difference in percent between the straight line fitting the actual transfer curve after removing offset
error, and the straight line which fits the ideal transfer curve. See Figure 14.
[7]
The absolute error (ET) is the maximum difference between the center of the steps of the actual transfer curve of the non-calibrated
ADC and the ideal transfer curve. See Figure 14.
[8]
See Figure 13.
LPC2XXX
20 kΩ
ADC IN[y]
ADC IN[y]SAMPLE
3 pF
Rvsi
5 pF
VEXT
VSS(IO), VSS(CORE)
002aae280
Fig 13. Suggested ADC interface - LPC2921/2923/2925 ADC1/2 IN[y] pin
LPC2921_23_25_3
Product data sheet
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NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
offset
error
EO
gain
error
EG
1023
1022
1021
1020
1019
1018
(2)
7
code
out
(1)
6
5
(5)
4
(4)
3
(3)
2
1 LSB
(ideal)
1
0
1
2
3
4
5
6
7
1018
1019
1020
1021
1022
1023
1024
VIA (LSBideal)
offset error
EO
002aae703
(1) Example of an actual transfer curve.
(2) The ideal transfer curve.
(3) Differential linearity error (ED).
(4) Integral non-linearity (EL(adj)).
(5) Center of a step of the actual transfer curve.
Fig 14. ADC characteristics
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Product data sheet
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8.1 Power consumption
002aae241
80
IDD(CORE)
(mA)
60
40
20
0
10
50
90
130
core frequency (MHz)
Conditions: Tamb = 25 °C; active mode entered executing code from flash; core voltage 1.8 V; all
peripherals enabled but not configured to run.
Fig 15. IDD(CORE) at different core frequencies (active mode)
002aae240
80
IDD(CORE)
(mA)
125 MHz
60
100 MHz
80 MHz
40
40 MHz
20
10 MHz
0
1.7
1.8
1.9
core voltage (V)
Conditions: Tamb = 25 °C; active mode entered executing code from flash; all peripherals enabled
but not configured to run.
Fig 16. IDD(CORE) at different core voltages VDD(CORE) (active mode)
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ARM9 microcontroller with CAN, LIN, and USB
002aae239
80
IDD(CORE)
(mA)
60
125 MHz
100 MHz
80 MHz
40
40 MHz
20
10 MHz
0
−40
−15
10
35
60
85
temperature (°C)
Conditions: active mode entered executing code from flash; core voltage 1.8 V; all peripherals
enabled but not configured to run.
Fig 17.
IDD(CORE) at different temperatures (active mode)
8.2 Electrical pin characteristics
002aae689
500
VOL
(mV)
400
85 °C
25 °C
0 °C
−40 °C
300
200
100
0
1.0
2.0
3.0
4.0
5.0
6.0
IOL(mA)
VDD(IO) = 3.3 V.
Fig 18. Typical LOW-level output voltage versus LOW-level output current
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Product data sheet
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ARM9 microcontroller with CAN, LIN, and USB
002aae690
3.5
VOH
(V)
85 °C
25 °C
0 °C
−40 °C
3.0
2.5
2.0
1.0
2.0
3.0
4.0
5.0
6.0
IOH (mA)
VDD(IO) = 3.3 V.
Fig 19. Typical HIGH-level output voltage versus HIGH-level output current
002aae691
80
II(pd)
(μA)
70
VDD(IO) = 3.6 V
3.0 V
2.7 V
60
50
40
−40
−15
10
35
60
85
temperature (°C)
VI = 3.3 V.
Fig 20. Typical pull-down current versus temperature
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Product data sheet
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NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
002aae692
−20
II(pu)
(μA)
VDD(IO) = 2.7 V
−40
3.3 V
−60
3.6 V
−80
−100
−40
−15
10
35
60
85
temperature (°C)
VI = 0 V.
Fig 21. Typical pull-up current versus temperature
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ARM9 microcontroller with CAN, LIN, and USB
9. Dynamic characteristics
9.1 Dynamic characteristics: I/O and CLK_OUT pins, internal clock,
oscillators, PLL, and CAN
Table 33. Dynamic characteristics
VDD(CORE) = VDD(OSC_PLL); VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; all voltages are measured with respect to
ground; positive currents flow into the IC; unless otherwise specified.[1]
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
tTHL
HIGH to LOW
transition time
CL = 30 pF
4
-
13.8
ns
tTLH
LOW to HIGH
transition time
CL = 30 pF
4
-
13.8
ns
clock frequency
on pin CLK_OUT
-
-
40
MHz
I/O pins
CLK_OUT pin
fclk
Internal clock
fclk(sys)
system clock
frequency
[2]
10
-
125
MHz
Tclk(sys)
system clock period
[2]
8
-
100
ns
0.4
0.5
0.6
MHz
-
6
-
μs
10
-
100
MHz
-
500
-
μs
Low-power ring oscillator
fref(RO)
RO reference
frequency
tstartup
start-up time
at maximum frequency
fi(osc)
oscillator input
frequency
maximum frequency is the
clock input of an external
clock source applied to the
XIN_OSC pin
tstartup
start-up time
at maximum frequency
[3]
Oscillator
[3]
[4]
PLL
fi(PLL)
PLL input frequency
10
-
25
MHz
fo(PLL)
PLL output frequency
10
-
160
MHz
156
-
320
MHz
ta(clk)
clock access time
-
-
63.4
ns
ta(A)
address access time
-
-
60.3
ns
-
0.4
1
ns
CCO; direct mode
Jitter specification for CAN
tjit(cc)(p-p)
cycle to cycle jitter
(peak-to-peak value)
on CAN TXDC pin
[3]
[1]
All parameters are guaranteed over the virtual junction temperature range by design. Pre-testing is performed at Tamb = 85 °C ambient
temperature on wafer level. Cased products are tested at Tamb = 25 °C (final testing). Both pre-testing and final testing use correlated
test conditions to cover the specified temperature and power supply voltage range.
[2]
See Table 24.
[3]
This parameter is not part of production testing or final testing, hence only a typical value is stated.
[4]
Oscillator start-up time depends on the quality of the crystal. For most crystals it takes about 1000 clock pulses until the clock is fully
stable.
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ARM9 microcontroller with CAN, LIN, and USB
002aae373
520
1.9 V
fref(RO)
(kHz)
1.8 V
1.7 V
510
500
490
480
−40
−15
10
35
60
85
temperature (°C)
Fig 22. Low-power ring oscillator thermal characteristics
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9.2 USB interface
Table 34. Dynamic characteristics: USB pins (full-speed)
CL = 50 pF; Rpu = 1.5 kΩ on D+ to VDD(3V3), unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
tr
rise time
10 % to 90 %
8.5
-
13.8
ns
tf
fall time
10 % to 90 %
7.7
-
13.7
ns
tFRFM
differential rise and fall time
matching
tr/tf
-
-
109
%
VCRS
output signal crossover voltage
1.3
-
2.0
V
tFEOPT
source SE0 interval of EOP
see Figure 23
160
-
175
ns
tFDEOP
source jitter for differential transition
to SE0 transition
see Figure 23
−2
-
+5
ns
tJR1
receiver jitter to next transition
−18.5
-
+18.5
ns
tJR2
receiver jitter for paired transitions
10 % to 90 %
−9
-
+9
ns
tEOPR1
EOP width at receiver
must reject as
EOP; see
Figure 23
[1]
40
-
-
ns
tEOPR2
EOP width at receiver
must accept as
EOP; see
Figure 23
[1]
82
-
-
ns
[1]
Characterized but not implemented as production test. Guaranteed by design.
TPERIOD
crossover point
extended
crossover point
differential
data lines
source EOP width: tFEOPT
differential data to
SE0/EOP skew
n × TPERIOD + tFDEOP
receiver EOP width: tEOPR1, tEOPR2
002aab561
Fig 23. Differential data-to-EOP transition skew and EOP width
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9.3 Dynamic characteristics: I2C-bus interface
Table 35. Dynamic characteristic: I2C-bus pins
VDD(CORE) = VDD(OSC_PLL); VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; all voltages are measured with respect to
ground; positive currents flow into the IC; unless otherwise specified[1]
Symbol
Parameter
output fall time
tf(o)
Conditions
Min
VIH to VIL
20 + 0.1 ×
Cb[3]
Typ[2]
Max
Unit
-
-
ns
[1]
All parameters are guaranteed over the virtual junction temperature range by design. Pre-testing is performed at Tamb = 85 °C ambient
temperature on wafer level. Cased products are tested at Tamb = 25 °C (final testing). Both pre-testing and final testing use correlated
test conditions to cover the specified temperature and power supply voltage range.
[2]
Typical ratings are not guaranteed. The values listed are at room temperature (25 °C), nominal supply voltages.
[3]
Bus capacitance Cb in pF, from 10 pF to 400 pF.
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9.4 Dynamic characteristics: SPI
Table 36. Dynamic characteristics of SPI pins
VDD(CORE) = VDD(OSC_PLL) ; VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; Tvj = −40 °C to +85 °C; all voltages are
measured with respect to ground; positive currents flow into the IC; unless otherwise specified.[1]
Symbol
SPI operating frequency
fSPI
tsu(SPI_MISO)
[1]
Parameter
SPI_MISO set-up time
Conditions
Min
master operation
1⁄
Typ
Max
Unit
65024fclk(SPI)
-
1⁄
slave operation
1⁄
2fclk(SPI)
MHz
65024fclk(SPI)
-
1⁄
4fclk(SPI) MHz
Tamb = 25 °C;
measured in
SPI Master
mode; see
Figure 24
-
11
-
ns
All parameters are guaranteed over the virtual junction temperature range by design. Pre-testing is performed at Tamb = 85 °C ambient
temperature on wafer level. Cased products are tested at Tamb = 25 °C (final testing). Both pre-testing and final testing use correlated
test conditions to cover the specified temperature and power supply voltage range.
shifting edges
SCKn
sampling edges
SDOn
SDIn
tsu(SPI_MISO)
002aae695
Fig 24. SPI data input set-up time in SSP Master mode
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9.5 Dynamic characteristics: flash memory and EEPROM
Table 37. Flash characteristics
Tamb = −40 °C to +85 °C; VDD(CORE) = VDD(OSC_PLL); VDD(IO) = 2.7 V to 3.6 V;
VDDA(ADC3V3) = 3.0 V to 3.6 V; all voltages are measured with respect to ground.
Symbol
Parameter
Nendu
endurance
tret
retention time
Conditions
[1]
Min
Typ
Max
Unit
10000
-
-
cycles
powered
10
-
-
years
unpowered
20
-
-
years
tprog
programming time
word
0.95
1
1.05
ms
ter
erase time
global
95
100
105
ms
sector
95
100
105
ms
tinit
initialization time
-
-
150
μs
twr(pg)
page write time
0.95
1
1.05
ms
tfl(BIST)
flash word BIST time
-
38
70
ns
ta(clk)
clock access time
-
-
63.4
ns
ta(A)
address access time
-
-
60.3
ns
[1]
Number of program/erase cycles.
Table 38. EEPROM characteristics
Tamb = −40 °C to +85 °C; VDD(CORE) = VDD(OSC_PLL); VDD(IO) = 2.7 V to 3.6 V;
VDDA(ADC3V3) = 3.0 V to 3.6 V; all voltages are measured with respect to ground.
LPC2921_23_25_3
Product data sheet
Symbol
Parameter
Conditions
fclk
clock frequency
Nendu
endurance
tret
retention time
powered
Min
Typ
Max
Unit
200
375
400
kHz
100000
500000
-
cycles
10
-
-
years
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9.6 Dynamic characteristics: ADC1/2
Table 39. ADC dynamic characteristics
VDD(CORE) = VDD(OSC_PLL); VDD(IO) = 2.7 V to 3.6 V; VDDA(ADC3V3) = 3.0 V to 3.6 V; all voltages are measured with respect to
ground.[1]
Symbol
Parameter
Conditions
fi(ADC)
ADC input frequency
fs(max)
maximum sampling rate
tconv
Min
Typ
Max
Unit
4
-
4.5
MHz
resolution 2 bit
-
-
1500 ksample/s
resolution 10 bit
-
-
400
ksample/s
In number of ADC
clock cycles
3
-
11
cycles
In number of bits
2
-
10
bits
[2]
conversion time
fi(ADC) = 4.5 MHz;
fs = fi(ADC) / (n + 1) with
n = resolution
[1]
All parameters are guaranteed over the virtual junction temperature range by design. Pre-testing is performed at Tamb = 85 °C ambient
temperature on wafer level. Cased products are tested at Tamb = 25 °C (final testing). Both pre-testing and final testing use correlated
test conditions to cover the specified temperature and power supply voltage range.
[2]
Duty cycle clock should be as close as possible to 50 %.
10. Application information
10.1 Operating frequency selection
The LPC2921/2923/2925 is specified to operate at a maximum frequency of 125 MHz,
maximum temperature of 85 °C, and maximum core voltage of 1.89 V. Figure 25 and
Figure 26 show that the user can achieve higher operating frequencies for the
LPC2921/2923/2925 by controlling the temperature and the core voltage accordingly.
002aae194
145
core
frequency
(MHz)
135
VDD(CORE) = 1.95 V
VDD(CORE) = 1.8 V
125
VDD(CORE) = 1.65 V
115
105
25
45
65
85
temperature (°C)
Fig 25. Core operating frequency versus temperature for different core voltages
LPC2921_23_25_3
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002aae193
145
core
frequency
(MHz)
135
125
25 °C
45 °C
65 °C
85 °C
115
105
1.65
1.75
1.85
1.95
core voltage (V)
Fig 26. Core operating frequency versus core voltage for different temperatures
10.2 Suggested USB interface solutions
VDD(IO)
USB_UP_LED
USB_CONNECT
LPC29xx
SoftConnect switch
R1
1.5 kΩ
USB_VBUS
USB_D+ RS = 33 Ω
USB_D−
USB-B
connector
RS = 33 Ω
VSS(IO)
002aae149
Fig 27. LPC2921/2923/2925 USB interface on a self-powered device
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VDD(IO)
R2
LPC29xx
USB_UP_LED
R1
1.5 kΩ
USB_VBUS
USB_D+ RS = 33 Ω
USB-B
connector
USB_D− RS = 33 Ω
VSS(IO)
002aae150
Fig 28. LPC2921/2923/2925 USB interface on a bus-powered device
10.3 SPI signal forms
SCKn (CPOL = 0)
SCKn (CPOL = 1)
SDOn
MSB OUT
DATA VALID
LSB OUT
SDIn
MSB IN
DATA VALID
LSB IN
CPHA = 1
SDOn
MSB OUT
DATA VALID
LSB OUT
SDIn
MSB IN
DATA VALID
LSB IN
CPHA = 0
002aae693
Fig 29. SPI timing in master mode
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SCKn (CPOL = 0)
SCKn (CPOL = 1)
SDIn
MSB IN
DATA VALID
LSB IN
SDOn
MSB OUT
DATA VALID
LSB OUT
CPHA = 1
SDIn
MSB IN
DATA VALID
LSB IN
SDOn
MSB OUT
DATA VALID
LSB OUT
CPHA = 0
002aae694
Fig 30. SPI timing in slave mode
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10.4 XIN_OSC input
The input voltage to the on-chip oscillators is limited to 1.8 V. If the oscillator is driven by a
clock in slave mode, it is recommended that the input be coupled through a capacitor with
Ci = 100 pF. To limit the input voltage to the specified range, choose an additional
capacitor to ground Cg which attenuates the input voltage by a factor Ci/(Ci + Cg). In slave
mode, a minimum of 200 mV (RMS) is needed. For more details see the LPC29xx User
manual UM10316.
LPC29xx
XIN_OSC
Ci
100 pF
Cg
002aae730
Fig 31. Slave mode operation of the on-chip oscillator
10.5 XIN_OSC Printed Circuit Board (PCB) layout guidelines
The crystal should be connected on the PCB as close as possible to the oscillator input
and output pins of the chip. Take care that the load capacitors Cx1 and Cx2, and Cx3 in
case of third overtone crystal usage, have a common ground plane. The external
components must also be connected to the ground plain. Loops must be made as small
as possible, in order to keep the noise coupled in via the PCB as small as possible. Also
parasitics should stay as small as possible. Values of Cx1 and Cx2 should be chosen
smaller accordingly to the increase in parasitics of the PCB layout.
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11. Package outline
LQFP100: plastic low profile quad flat package; 100 leads; body 14 x 14 x 1.4 mm
SOT407-1
c
y
X
A
51
75
50
76
ZE
e
E HE
A A2
(A 3)
A1
w M
θ
bp
Lp
pin 1 index
L
100
detail X
26
1
25
ZD
e
v M A
w M
bp
D
B
HD
v M B
0
5
10 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D (1)
E (1)
e
mm
1.6
0.15
0.05
1.45
1.35
0.25
0.27
0.17
0.20
0.09
14.1
13.9
14.1
13.9
0.5
HD
HE
16.25 16.25
15.75 15.75
L
Lp
v
w
y
1
0.75
0.45
0.2
0.08
0.08
Z D (1) Z E (1)
1.15
0.85
1.15
0.85
θ
7o
o
0
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
SOT407-1
136E20
MS-026
JEITA
EUROPEAN
PROJECTION
ISSUE DATE
00-02-01
03-02-20
Fig 32. Package outline (LQFP100)
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12. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note AN10365 “Surface mount reflow
soldering description”.
12.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
12.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
• Through-hole components
• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
•
•
•
•
•
•
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
12.3 Wave soldering
Key characteristics in wave soldering are:
• Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
• Solder bath specifications, including temperature and impurities
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12.4 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 33) than a SnPb process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 40 and 41
Table 40.
SnPb eutectic process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (°C)
Volume (mm3)
< 350
≥ 350
< 2.5
235
220
≥ 2.5
220
220
Table 41.
Lead-free process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (°C)
Volume (mm3)
< 350
350 to 2000
> 2000
< 1.6
260
260
260
1.6 to 2.5
260
250
245
> 2.5
250
245
245
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 33.
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temperature
maximum peak temperature
= MSL limit, damage level
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 33. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
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13. Abbreviations
Table 42.
Abbreviations list
Abbreviation
Description
AF
Acceptance Filter
AHB
Advanced High-performance Bus
AMBA
Advanced Microcontroller Bus Architecture
APB
ARM Peripheral Bus
CCO
Current Controlled Oscillator
CISC
Complex Instruction Set Computers
DMA
Direct Memory Access
DSP
Digital Signal Processing
DTL
Device Transaction Level
EOP
End Of Packet
ETB
Embedded Trace Buffer
ETM
Embedded Trace Macrocell
FIQ
Fast Interrupt reQuest
GPDMA
General Purpose DMA
GPIO
General Purpose Input/Output
IRQ
Interrupt ReQuest
LIN
Local Interconnect Network
LUT
Look-Up Table
MAC
Media Access Control
MSC
Modulation and Sampling Control
PHY
PHYsical layer
PLL
Phase-Locked Loop
Q-SPI
Queued SPI
RISC
Reduced Instruction Set Computer
SCU
System Control Unit
SFSP
SCU Function Select Port
TTL
Transistor-Transistor Logic
UART
Universal Asynchronous Receiver Transmitter
USB
Universal Serial Bus
14. References
LPC2921_23_25_3
Product data sheet
[1]
UM10316 — LPC29xx user manual
[2]
ARM — ARM web site
[3]
ARM-SSP — ARM primecell synchronous serial port (PL022) technical reference
manual
[4]
CAN — ISO 11898-1: 2002 road vehicles - Controller Area Network (CAN) - part 1:
data link layer and physical signalling
[5]
LIN — LIN specification package, revision 2.0
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15. Revision history
Table 43.
Revision history
Document ID
Release date
Data sheet status
LPC2921_23_25_3
20100414
Product data sheet
Modifications:
•
•
•
Change notice Supersedes
LPC2921_23_25_2
Section 1: Target market “medical” removed.
Document template updated.
USB logo added.
LPC2921_23_25_2
20091208
Product data sheet
LPC2921_23_25_1
20090615
Preliminary data sheet -
LPC2921_23_25_3
Product data sheet
-
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LPC2921_23_25_1
-
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16. Legal information
16.1 Data sheet status
Document status[1][2]
Product status[3]
Definition
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
16.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
16.3 Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on a weakness or default in the
customer application/use or the application/use of customer’s third party
customer(s) (hereinafter both referred to as “Application”). It is customer’s
sole responsibility to check whether the NXP Semiconductors product is
suitable and fit for the Application planned. Customer has to do all necessary
testing for the Application in order to avoid a default of the Application and the
product. NXP Semiconductors does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial sale — NXP Semiconductors
products are sold subject to the general terms and conditions of commercial
sale, as published at http://www.nxp.com/profile/terms, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from national authorities.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
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product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
16.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
17. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
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18. Contents
1
2
3
3.1
4
5
5.1
5.2
5.2.1
5.2.2
6
6.1
6.2
6.3
6.4
6.5
6.6
6.6.1
6.6.2
6.6.3
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features and benefits . . . . . . . . . . . . . . . . . . . . 1
Ordering information . . . . . . . . . . . . . . . . . . . . . 3
Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 3
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pinning information . . . . . . . . . . . . . . . . . . . . . . 5
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5
General description . . . . . . . . . . . . . . . . . . . . . 5
LQFP100 pin assignment . . . . . . . . . . . . . . . . . 5
Functional description . . . . . . . . . . . . . . . . . . . 9
Architectural overview . . . . . . . . . . . . . . . . . . . 9
ARM968E-S processor . . . . . . . . . . . . . . . . . . . 9
On-chip flash memory system . . . . . . . . . . . . 10
On-chip static RAM. . . . . . . . . . . . . . . . . . . . . 10
Memory map. . . . . . . . . . . . . . . . . . . . . . . . . . 11
Reset, debug, test, and power description . . . 12
Reset and power-up behavior . . . . . . . . . . . . 12
Reset strategy . . . . . . . . . . . . . . . . . . . . . . . . 12
IEEE 1149.1 interface pins (JTAG boundary-scan
test). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.6.3.1
ETM/ETB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.6.4
Power supply pins . . . . . . . . . . . . . . . . . . . . . 13
6.7
Clocking strategy . . . . . . . . . . . . . . . . . . . . . . 13
6.7.1
Clock architecture . . . . . . . . . . . . . . . . . . . . . . 13
6.7.2
Base clock and branch clock relationship. . . . 14
6.8
Flash memory controller . . . . . . . . . . . . . . . . . 17
6.8.1
Functional description. . . . . . . . . . . . . . . . . . . 17
6.8.2
Flash layout . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.8.3
Flash bridge wait-states . . . . . . . . . . . . . . . . . 19
6.8.4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . 19
6.8.5
Clock description . . . . . . . . . . . . . . . . . . . . . . 19
6.8.6
EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.9
General Purpose DMA (GPDMA) controller . . 20
6.9.1
DMA support for peripherals. . . . . . . . . . . . . . 20
6.9.2
Clock description . . . . . . . . . . . . . . . . . . . . . . 20
6.10
USB interface . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.10.1
USB device controller . . . . . . . . . . . . . . . . . . . 20
6.10.2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . 21
6.10.3
Clock description . . . . . . . . . . . . . . . . . . . . . . 21
6.11
General subsystem. . . . . . . . . . . . . . . . . . . . . 22
6.11.1
General subsystem clock description . . . . . . . 22
6.11.2
Chip and feature identification . . . . . . . . . . . . 22
6.11.3
System Control Unit (SCU). . . . . . . . . . . . . . . 22
6.11.4
Event router . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.11.4.1 Pin description . . . . . . . . . . . . . . . . . . . . . . . . 23
6.12
Peripheral subsystem . . . . . . . . . . . . . . . . . . . 23
6.12.1
6.12.2
6.12.2.1
6.12.2.2
6.12.3
6.12.3.1
6.12.3.2
6.12.4
6.12.4.1
6.12.4.2
6.12.5
6.12.5.1
6.12.5.2
6.12.5.3
6.12.6
6.12.6.1
6.12.6.2
6.12.6.3
6.13
6.13.1
6.13.1.1
6.13.1.2
6.13.2
6.13.2.1
6.13.3
6.13.3.1
6.14
6.14.1
6.14.2
6.14.3
6.14.4
6.14.4.1
6.14.4.2
6.14.4.3
6.14.5
6.14.5.1
6.14.5.2
6.14.5.3
6.14.5.4
6.14.5.5
6.14.6
6.14.6.1
6.14.6.2
6.14.7
6.14.7.1
6.14.7.2
Peripheral subsystem clock description. . . . .
Watchdog timer . . . . . . . . . . . . . . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
UARTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Serial Peripheral Interface (SPI) . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
General-purpose I/O . . . . . . . . . . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Networking subsystem. . . . . . . . . . . . . . . . . .
CAN gateway . . . . . . . . . . . . . . . . . . . . . . . . .
Global acceptance filter . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
LIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
I2C-bus serial I/O controllers . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Modulation and Sampling Control SubSystem
(MSCSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Analog-to-digital converter . . . . . . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Pulse Width Modulator (PWM). . . . . . . . . . . .
Functional description . . . . . . . . . . . . . . . . . .
Synchronizing the PWM counters . . . . . . . . .
Master and slave mode . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Timers in the MSCSS. . . . . . . . . . . . . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
Quadrature Encoder Interface (QEI) . . . . . . .
Pin description . . . . . . . . . . . . . . . . . . . . . . . .
Clock description . . . . . . . . . . . . . . . . . . . . . .
23
23
24
24
24
25
25
25
26
26
26
27
27
28
28
28
28
29
29
29
29
29
30
30
30
31
31
31
33
34
34
34
35
36
36
36
37
38
38
38
38
39
39
39
40
40
continued >>
LPC2921_23_25_3
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 03 — 14 April 2010
© NXP B.V. 2010. All rights reserved.
83 of 84
LPC2921/2923/2925
NXP Semiconductors
ARM9 microcontroller with CAN, LIN, and USB
6.15
Power, Clock, and Reset control SubSystem
(PCRSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.15.1
Clock description . . . . . . . . . . . . . . . . . . . . . .
6.15.2
Clock Generation Unit (CGU0) . . . . . . . . . . . .
6.15.2.1 Functional description. . . . . . . . . . . . . . . . . . .
6.15.2.2 PLL functional description . . . . . . . . . . . . . . .
6.15.2.3 Pin description . . . . . . . . . . . . . . . . . . . . . . . .
6.15.3
Clock generation for USB (CGU1) . . . . . . . . .
6.15.3.1 Pin description . . . . . . . . . . . . . . . . . . . . . . . .
6.15.4
Reset Generation Unit (RGU). . . . . . . . . . . . .
6.15.4.1 Functional description. . . . . . . . . . . . . . . . . . .
6.15.4.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . .
6.15.5
Power Management Unit (PMU). . . . . . . . . . .
6.15.5.1 Functional description. . . . . . . . . . . . . . . . . . .
6.16
Vectored interrupt controller . . . . . . . . . . . . . .
6.16.1
Functional description. . . . . . . . . . . . . . . . . . .
6.16.2
Clock description . . . . . . . . . . . . . . . . . . . . . .
7
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . .
8
Static characteristics. . . . . . . . . . . . . . . . . . . .
8.1
Power consumption . . . . . . . . . . . . . . . . . . . .
8.2
Electrical pin characteristics . . . . . . . . . . . . . .
9
Dynamic characteristics . . . . . . . . . . . . . . . . .
9.1
Dynamic characteristics: I/O and CLK_OUT
pins, internal clock, oscillators, PLL, and
CAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2
USB interface . . . . . . . . . . . . . . . . . . . . . . . . .
9.3
Dynamic characteristics: I2C-bus interface. . .
9.4
Dynamic characteristics: SPI . . . . . . . . . . . . .
9.5
Dynamic characteristics: flash memory and
EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.6
Dynamic characteristics: ADC1/2 . . . . . . . . .
10
Application information. . . . . . . . . . . . . . . . . .
10.1
Operating frequency selection . . . . . . . . . . . .
10.2
Suggested USB interface solutions . . . . . . . .
10.3
SPI signal forms . . . . . . . . . . . . . . . . . . . . . . .
10.4
XIN_OSC input . . . . . . . . . . . . . . . . . . . . . . . .
10.5
XIN_OSC Printed Circuit Board (PCB)
layout guidelines . . . . . . . . . . . . . . . . . . . . . . .
11
Package outline . . . . . . . . . . . . . . . . . . . . . . . .
12
Soldering of SMD packages . . . . . . . . . . . . . .
12.1
Introduction to soldering . . . . . . . . . . . . . . . . .
12.2
Wave and reflow soldering . . . . . . . . . . . . . . .
12.3
Wave soldering . . . . . . . . . . . . . . . . . . . . . . . .
12.4
Reflow soldering . . . . . . . . . . . . . . . . . . . . . . .
13
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . .
14
References . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
Revision history . . . . . . . . . . . . . . . . . . . . . . . .
16
Legal information. . . . . . . . . . . . . . . . . . . . . . .
40
41
42
42
45
46
47
47
47
48
48
49
49
51
51
52
53
55
60
61
64
16.1
16.2
16.3
16.4
17
18
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
81
81
81
82
82
83
64
66
67
68
69
70
70
70
71
72
74
74
75
76
76
76
76
77
79
79
80
81
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2010.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
Date of release: 14 April 2010
Document identifier: LPC2921_23_25_3