MAXIM MAXQ61CE

19-5231; Rev 0; 4/10
16-Bit Microcontroller with Infrared Module
Features
The MAXQ61C is a low-power, 16-bit MAXQ® micro-
S High-Performance, Low-Power, 16-Bit RISC Core
controller designed for low-power applications including
universal remote controls, consumer electronics, and
white goods. The device combines a powerful 16-bit
RISC microcontroller and integrated peripherals including two universal synchronous/asynchronous receivertransmitters (USARTs) and an SPI™ master/slave communications port, along with an IR module with carrier
frequency generation and flexible port I/O capable of
multiplexed keypad control.
S DC to 12MHz Operation Across Entire Operating Range
S 1.70V to 3.6V Operating Voltage
S 33 Total Instructions for Simplified Programming
S Three Independent Data Pointers Accelerate Data
Movement with Automatic Increment/Decrement
S Dedicated Pointer for Direct Read from Code Space
S 16-Bit Instruction Word, 16-Bit Data Bus
S 16 x 16-Bit General-Purpose Working Registers
S Memory Features
80KB Application ROM
2KB Data SRAM
S Additional Peripherals
Power-Fail Warning
Power-On Reset (POR)/Brownout Reset
Automatic IR Carrier Frequency Generation and
Modulation
Two 16-Bit Programmable Timers/Counters with
Prescaler and Capture/Compare
One SPI Port and Two USART Ports
Programmable Watchdog Timer
8kHz Nanopower Ring Oscillator Wake-Up Timer
Up to 32 General-Purpose I/Os (J, K, and X
Versions Only)
S Low Power Consumption
0.2µA (typ), 2.0µA (max) in Stop Mode,
TA = +25NC, Power-Fail Monitor Disabled
2.0mA (typ) at 12MHz in Active Mode
The device includes 80KB of ROM memory and 2KB of
data SRAM.
For the ultimate in low-power battery-operated performance, the device includes an ultra-low-power stop
mode (0.2µA typ). In this mode, the minimum amount of
circuitry is powered. Wake-up sources include external
interrupts, the power-fail interrupt, and a timer interrupt.
The microcontroller runs from a wide 1.70V to 3.6V operating voltage.
Applications
Remote Controls
Battery-Powered Portable Equipment
Consumer Electronics
Home Appliances
White Goods
Ordering Information/Selector Guide
PART
TEMP RANGE
OPERATING
VOLTAGE (V)
PROGRAM
MEMORY (KB)
DATA
MEMORY (KB)
GPIO
MAXQ61CA-xxxx+
0NC to +70NC
1.7 to 3.6
80 ROM
2
20
32 TQFN-EP*
MAXQ61CE-xxxx+
0NC to +70NC
1.7 to 3.6
80 ROM
2
20
32 LQFP
MAXQ61CJ-xxxx+
0NC to +70NC
1.7 to 3.6
80 ROM
2
32
44 TQFN-EP*
MAXQ61CK-xxxx+
0NC to +70NC
1.7 to 3.6
80 ROM
2
32
44 TQFP
MAXQ61CX-xxxx+
0NC to +70NC
1.7 to 3.6
80 ROM
2
32
Bare die
PIN-PACKAGE
Note: Contact the factory for information about masked ROM devices.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
MAXQ is a registered trademark of Maxim Integrated Products, Inc.
SPI is a trademark of Motorola, Inc.
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAXQ61C
General Description
MAXQ61C
16-Bit Microcontroller with Infrared Module
TABLE OF CONTENTS
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SPI Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Microprocessor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Stack Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Utility ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
IR Carrier Generation and Modulation Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Carrier Generation Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
IR Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
IR Transmit—Independent External Carrier and Modulator Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
IR Receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Carrier Burst-Count Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
16-Bit Timers/Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
USART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Serial Peripheral Interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
General-Purpose I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
On-Chip Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power-Fail Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Grounds and Bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Additional Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Deviations from the MAXQ610 User’s Guide for the MAXQ61C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Development and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2 _______________________________________________________________________________________
16-Bit Microcontroller with Infrared Module
Figure 1. IR Transmit Frequency Shifting Example (IRCFME = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 2. IR Transmit Carrier Generation and Carrier Modulator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 3. IR Transmission Waveform (IRCFME = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 4. External IRTXM (Modulator) Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 5. IR Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 6. Receive Burst-Count Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 7. SPI Master Communication Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 8. SPI Slave Communication Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 9. On-Chip Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 10. Power-Fail Detection During Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 11. Stop Mode Power-Fail Detection States with Power-Fail Monitor Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 12. Stop Mode Power-Fail Detection with Power-Fail Monitor Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
LIST OF TABLES
Table 1. Watchdog Interrupt Timeout (Sysclk = 12MHz, CD[1:0] = 00) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 2. USART Mode Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 3. Power-Fail Detection States During Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 4. Stop Mode Power-Fail Detection States with Power-Fail Monitor Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 5. Stop Mode Power-Fail Detection States with Power-Fail Monitor Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . 24
_______________________________________________________________________________________ 3
MAXQ61C
LIST OF FIGURES
MAXQ61C
16-Bit Microcontroller with Infrared Module
ABSOLUTE MAXIMUM RATINGS
Voltage Range on VDD with Respect to GND......-0.3V to +3.6V
Voltage Range on Any Lead with
Respect to GND Except VDD................ -0.3V to (VDD + 0.5V)
Continuous Power Dissipation (TA = +70NC)
32-Pin TQFN (single-layer board)
(derate 21.3mW/NC above +70NC)..........................1702.1mW
32-Pin TQFN (multilayer board)
(derate 34.5mW/NC above +70NC)..........................2758.6mW
32-Pin LQFP (multilayer board)
(derate 20.7mW/NC above +70NC)..........................1652.9mW
44-Pin TQFN (single-layer board)
(derate 27mW/NC above +70NC).............................2162.2mW
44-Pin TQFN (multilayer board)
(derate 37mW/NC above +70NC)................................2963mW
Operating Temperature Range.............................. 0NC to +70NC
Storage Temperature Range............................. -65NC to +150NC
Lead Temperature (excluding dice; soldering, 10s).......+300NC
Soldering Temperature (reflow).......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
(VDD = VRST to 3.6V, TA = 0NC to +70NC, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage
1.8V Internal Regulator
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
VDD
VRST
3.6
V
VREG18
1.62
1.8
1.98
V
Power-Fail Warning Voltage for
Supply
VPFW
Monitors VDD
1.75
1.8
1.85
V
Power-Fail Reset Voltage
VRST
Monitors VDD (Note 2)
1.64
1.67
1.70
V
POR Voltage
VPOR
Monitors VDD
1.0
1.42
V
RAM Data-Retention Voltage
VDRV
(Note 3)
1.0
Active Current
IDD_1
Sysclk = 12MHz (Note 4)
2.5
3.75
mA
TA = +25NC
0.15
2.0
TA = 0°C +70NC
TA = +25NC
0.15
8
22
31
TA = 0°C to +70NC
27.6
38
IS1
Power-Fail Off
Stop-Mode Current
V
FA
IS2
Power-Fail On
Current Consumption During
Power-Fail
IPFR
(Note 5)
[(3 x IS2) +
((PCI - 3) x (IS1 +
INANO))]/PCI
FA
Power Consumption During
POR
IPOR
(Note 6)
100
nA
Stop-Mode Resume Time
tON
375 + (8192 x tHFXIN)
tPFM_ON
Power-Fail Warning Detection
Time
tPFW
Input Low Voltage for IRTX,
IRRX, RESET, and All Port Pins
VIL
VGND
0.3 x VDD
V
Input High Voltage for IRTX,
IRRX, RESET, and All Port Pins
VIH
0.7 x VDD
VDD
V
Input Hysteresis (Schmitt)
VIHYS
(Note 3)
(Notes 3, 7)
150
Fs
Power-Fail Monitor Startup Time
10
Fs
300
VDD = 3.3V, TA = +25NC
Fs
mV
Input Low Voltage for HFXIN
VIL_HFXIN
VGND
0.3 x VDD
V
Input High Voltage for HFXIN
VIH_HFXIN
0.7 x VDD
VDD
V
4 _______________________________________________________________________________________
16-Bit Microcontroller with Infrared Module
(VDD = VRST to 3.6V, TA = 0NC to +70NC, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
IRRX Input Filter Pulse-Width
Reject
tIRRX_R
IRRX Input Filter Pulse-Width
Accept
tIRRX_A
Output Low Voltage for IRTX
VOL_IRTX
CONDITIONS
50
ns
ns
1.0
1.0
VDD = 1.85V, IOL = 4.5mA
1.0
VDD = 3.6V, IOL = 11mA (Note 3)
VDD = 2.35V, IOL = 8mA (Note 3)
0.4
0.5
0.4
0.5
VDD = 1.85V, IOL = 4.5mA
0.4
0.5
VOH
IOH = -2mA
Input/Output Pin Capacitance
for All Port Pins
CIO
(Note 3)
RPU
UNITS
VDD = 2.35V, IOL = 10mA (Note 3)
Output High Voltage for IRTX
and All Port Pins
Input Pullup Resistor for
RESET, IRTX, IRRX, P0, P1, P2
MAX
VDD = 3.6V, IOL = 25mA (Note 3)
VOL
IL
TYP
300
Output Low Voltage for RESET
and All Port Pins (Note 8)
Input Leakage Current
MIN
Internal pullup disabled
VDD = 3.0V, VOL = 0.4V (Note 3)
VDD = 2.0V, VOL = 0.4V
VDD - 0.5
-100
V
V
VDD
V
15
pF
+100
nA
16
28
39
17
30
41
kW
EXTERNAL CRYSTAL/RESONATOR
Crystal/Resonator
fHFXIN
Crystal/Resonator Period
tHFXIN
Crystal/Resonator Warmup
Time
Oscillator Feedback Resistor
tXTAL_RDY
ROSCF
DC
From initial oscillation
(Note 3)
0.5
12
MHz
1/fHFXIN
ns
8192 x
tHFXIN
ms
1.0
1.5
MW
12
MHz
EXTERNAL CLOCK INPUT
External Clock Frequency
External Clock Period
External Clock Duty Cycle
fXCLK
DC
tXCLK
1/fXCLK
tXCLK_DUTY (Note 3)
System Clock Frequency
fCK
System Clock Period
tCK
45
ns
55
fHFXIN
HFXOUT = GND
%
MHz
fXCLK
1/fCK
ns
NANOPOWER RING
TA = +25NC
3.0
8.0
Nanopower Ring Frequency
fNANO
TA = +25NC, VDD = POR voltage
(Note 3)
1.7
2.4
Nanopower Ring Duty Cycle
tNANO
(Note 3)
40
Nanopower Ring Current
INANO
Typical at VDD = 1.64V,
TA = +25°C (Note 3)
40
20.0
kHz
60
%
400
nA
65,535/
fNANO
s
fCK/2
Hz
WAKE-UP TIMER
Wake-Up Timer Interval
tWAKEUP
1/fNANO
IR
Carrier Frequency
fIR
(Note 3)
_______________________________________________________________________________________ 5
MAXQ61C
RECOMMENDED OPERATING CONDITIONS (continued)
MAXQ61C
16-Bit Microcontroller with Infrared Module
SPI ELECTRICAL CHARACTERISTICS
(VDD = VRST to 3.6V, TA = 0NC to +70NC, unless otherwise noted.) (Note 9)
MAX
UNITS
SPI Master Operating Frequency
PARAMETER
1/tMCK
fCK/2
MHz
SPI Slave Operating Frequency
1/tSCK
fCK/4
MHz
SPI I/O Rise/Fall Time
tSPI_RF
23.6
ns
SCLK Output Pulse-Width High/
Low
tMCH,
tMCL
tMCK/2 tSPI_RF
ns
MOSI Output Hold Time After
SCLK Sample Edge
tMOH
tMCK/2 tSPI_RF
ns
MOSI Output Valid to Sample
Edge
tMOV
tMCK/2 tSPI_RF
ns
MISO Input Valid to SCLK Sample
Edge Rise/Fall Setup
tMIS
25
ns
MISO Input to SCLK Sample Edge
Rise/Fall Hold
tMIH
0
ns
SCLK Inactive to MOSI Inactive
tMLH
tMCK/2 tSPI_RF
ns
SCLK Input Pulse-Width High/Low
SYMBOL
CONDITIONS
CL = 15pF, pullup = 560W
MIN
TYP
8.3
tSCH, tSCL
tSCK/2
ns
SSEL Active to First Shift Edge
tSSE
tSPI_RF
ns
MOSI Input to SCLK Sample Edge
Rise/Fall Setup
tSIS
tSPI_RF
ns
MOSI Input from SCLK Sample
Edge Transition Hold
tSIH
tSPI_RF
ns
MISO Output Valid After SCLK
Shift Edge Transition
tSOV
SSEL Inactive
tSSH
tCK +
tSPI_RF
SCLK Inactive to SSEL Rising
tSD
tSPI_RF
MISO Output Disabled After SSEL
Edge Rise
2tSPI_RF
tSLH
ns
ns
ns
2tCK +
2tSPI_RF
ns
Note 1: Specifications to 0NC are guaranteed by design and are not production tested. Typical = +25NC, VDD = +3.3V, unless
otherwise noted.
Note 2: The power-fail reset and POR detectors are designed to operate in tandem to ensure that one or both of these signals
is active at all times when VDD < VRST, ensuring the device maintains the reset state until minimum operating voltage is
achieved.
Note 3: Guaranteed by design and not production tested.
Note 4: Measured on the VDD pin and the device not in reset. All inputs are connected to GND or VDD. Outputs do not source/
sink any current. The device is executing code from ROM memory.
Note 5: The power-check interval (PCI) can be set to always on, or to 1024, 2048, or 4096 nanopower ring clock cycles.
Note 6: Current consumption during POR when powering up while VDD is less than the POR release voltage.
Note 7: The minimum amount of time that VDD must be below VPFW before a power-fail event is detected; refer to the MAXQ610
User’s Guide for details.
Note 8: The maximum total current, IOH(MAX) and IOL(MAX), for all listed outputs combined should not exceed 32mA to satisfy the
maximum specified voltage drop. This does not include the IRTX output.
Note 9: AC electrical specifications are guaranteed by design and are not production tested.
6 _______________________________________________________________________________________
16-Bit Microcontroller with Infrared Module
HFXOUT
13
HFXIN
P1.7/INT7 29
12
GND
GND 30
11
REGOUT
IRTX 31
10
VDD
9
RESET
HFXOUT
13
HFXIN
P1.6/INT6 28
12
GND
4
5
6
7
8
P0.1/RX0
P0.2/TX0
P0.3/RX1
P0.4/TX1
P0.5/TBA0/TBA1
P0.6/TBB0
P0.7/TBB1
IRRX 32
+
P2.5/TDI
P2.4/TCK
GND
N.C.
N.C.
P3.7/INT15
P3.6/INT14
P3.5/INT13
29
28
27
26
25
24
23
8
P2.6/TMS
7
30
6
P2.7/TDO
5
31
4
P1.0/INT0
3
32
TOP VIEW
2
33
TQFN
(5mm × 5mm)
1
P0.7/TBB1
3
RESET
P0.6/TBB0
2
9
P0.5/TBA0/TBA1
1
P0.0/IRTXM
IRRX 32
MAXQ61C
P0.4/TX1
+
REGOUT
VDD
GND
14
14
10
P2.4/TCK
P1.5/INT5 27
P1.5/INT5 27
11
P2.5/TDI
N.C.
N.C.
EP
P2.6/TMS
15
15
IRTX 31
17
P1.4/INT4 26
P1.4/INT4 26
GND 30
18
N.C.
N.C.
P1.7/INT7 29
19
16
16
MAXQ61C
20
P1.3/INT3 25
P1.3/INT3 25
P1.6/INT6 28
P2.7/TDO
17
21
P0.3/RX1
18
P1.0/INT0
19
P1.1/INT1
P2.4/TCK
GND
20
22
P0.2/TX0
P2.5/TDI
21
23
P0.1/RX0
P2.6/TMS
22
P1.2/INT2
P2.7/TDO
23
24
P0.0/IRTXM
P1.1/INT1
24
TOP VIEW
P1.0/INT0
P1.2/INT2
TOP VIEW
LQFP
(7mm × 7mm)
P1.1/INT1
34
22
P3.4/INT12
P1.2/INT2
35
21
P3.3/INT11
P1.3/INT3
36
20
P3.2/INT10
P1.4/INT4
37
19
P3.1/INT9
P1.5/INT5
38
18
P3.0/INT8
P1.6/INT6
39
17
HFXOUT
P1.7/INT7
40
16
HFXIN
GND
41
15
GND
IRTX
42
14
REGOUT
IRRX
43
P0.0/IRTXM
44
MAXQ61C
EP
5
6
7
8
9
10
11
P0.5/TBA0/TBA1
P0.6/TBB0
P0.7/TBB1
P2.0/MOSI
P2.1/MISO
P2.2/SCLK
P2.3/SSEL
3
P0.3/RX1
4
2
P0.2/TX0
P0.4/TX1
1
P0.1/RX0
+
13
VDD
12
RESET
TQFN
(7mm × 7mm)
_______________________________________________________________________________________ 7
MAXQ61C
Pin Configurations
P2.7/TDO
P2.6/TMS
P2.5/TDI
P2.4/TCK
GND
N.C.
N.C.
P3.7/INT15
P3.6/INT14
P3.5/INT13
TOP VIEW
P1.0/INT0
Pin Configurations (continued)
33
32
31
30
29
28
27
26
25
24
23
P1.1/INT1 34
22
P3.4/INT12
P1.2/INT2 35
21
P3.3/INT11
P1.3/INT3 36
20
P3.2/INT10
P1.4/INT4 37
19
P3.1/INT9
18
P3.0/INT8
17
HFXOUT
P1.7/INT7 40
16
HFXIN
GND 41
15
GND
IRTX 42
14
REGOUT
IRRX 43
13
VDD
12
RESET
P1.5/INT5 38
MAXQ61C
P1.6/INT6 39
1
2
3
4
5
6
7
8
9
10
11
P0.3/RX1
P0.4/TX1
P0.5/TBA0/TBA1
P0.6/TBB0
P0.7/TBB1
P2.0/MOSI
P2.1/MISO
P2.2/SCLK
P2.3/SSEL
+
P0.2/TX0
P0.0/IRTXM 44
P0.1/RX0
MAXQ61C
16-Bit Microcontroller with Infrared Module
TQFP
(10mm × 10mm)
NOTE: CONTACT FACTORY FOR BARE DIE PAD CONFIGURATION.
8 _______________________________________________________________________________________
16-Bit Microcontroller with Infrared Module
PIN
BARE DIE
32 TQFNEP/LQFP
44 TQFNEP/TQFP
NAME
FUNCTION
POWER PINS
14
10
13
VDD
Supply Voltage
16
12
15
GND
Ground. Connect directly to the ground plane.
27, 40
17, 30
28, 41
GND
Ground. For low-current applications (< 10mA of GPIO current, exclusive of IRTX sink current), these pins can be left unconnected. If used,
they should be connected directly to the ground plane.
REGOUT
1.8V Regulator Output. This pin must be connected to ground through
a 1.0FF (ESR: 2–10W) external ceramic-chip capacitor. The capacitor
must be placed as close to this pin as possible. No devices other than
the capacitor should be connected to this pin.
EP
Exposed Pad (TQFN Only). For low-current applications (< 10mA of
GPIO current, exclusive of IRTX sink current), these pins can be left
unconnected. If used, they should be connected directly to the ground
plane.
15
—
11
—
14
—
RESET PINS
13
9
12
RESET
Digital, Active-Low Reset Input/Output. The device remains in reset
as long as this pin is low and begins executing from the utility ROM at
address 8000h when this pin returns to a high state. The pin includes
pullup current source; if this pin is driven by an external device, it should
be driven by an open-drain source capable of sinking in excess of 4mA.
This pin can be left unconnected if there is no need to place the device in
a reset state using an external signal. This pin is driven low as an output
when an internal reset condition occurs.
CLOCK PINS
17
13
16
HFXIN
18
14
17
HFXOUT
High-Frequency Crystal Input. Connect an external crystal or resonator between HFXIN and HFXOUT for use as the high-frequency system
clock. Alternatively, HFXIN is the input for an external, high-frequency
clock source when HFXOUT is connected to ground.
IR FUNCTION PINS
41
42
31
32
42
43
IRTX
IR Transmit Output. IR transmission pin capable of sinking 25mA. This
pin defaults to a high-impedance input with the weak pullup disabled
during all forms of reset. Software must configure this pin after release
from reset to remove the high-impedance input condition.
IRRX
IR Receive Input. This pin defaults to a high-impedance input with the
weak pullup disabled during all forms of reset. Software must configure
this pin after release from reset to remove the high-impedance input
condition.
_______________________________________________________________________________________ 9
MAXQ61C
Pin Description
MAXQ61C
16-Bit Microcontroller with Infrared Module
Pin Description (continued)
PIN
BARE DIE
32 TQFNEP/LQFP
44 TQFNEP/TQFP
NAME
FUNCTION
GENERAL-PURPOSE I/O AND SPECIAL FUNCTION PINS
Port 0 General-Purpose, Digital I/O Pins. These port pins function as
general-purpose I/O pins with their input and output states controlled by
the PD0, PO0, and PI0 registers. All port pins default to high-impedance
mode after a reset. Software must configure these pins after release
from reset to remove the high-impedance condition. All special functions must be enabled from software before they can be used.
GPIO PORT PIN
SPECIAL FUNCTION
IR Modulator Output
1
1
44
P0.0/IRTXM
P0.0
2
2
1
P0.1/RX0
P0.1
USART 0 Receive
3
3
2
P0.2/TX0
P0.2
USART 0 Transmit
4
4
3
P0.3/RX1
P0.3
USART 1 Receive
5
5
4
P0.4/TX1
P0.4
USART 1 Transmit
6
6
5
P0.5/TBA0/
TBA1
P0.5
Type B Timer 0 Pin A or Type B
Timer 1 Pin A
7
7
6
P0.6/TBB0
P0.6
Type B Timer 0 Pin B
8
8
7
P0.7/TBB1
P0.7
Type B Timer 1 Pin B
Port 1 General-Purpose, Digital I/O Pins with Interrupt Capability. These
port pins function as general-purpose I/O pins with their input and output states controlled by the PD1, PO1, and PI1 registers. All port pins
default to high-impedance mode after a reset. Software must configure
these pins after release from reset to remove the high-impedance condition. All external interrupts must be enabled from software before they
can be used.
GPIO PORT PIN
EXTERNAL INTERRUPT
32
22
33
P1.0/INT0
P1.0
INT0
33
23
34
P1.1/INT1
P1.1
INT1
34
24
35
P1.2/INT2
P1.2
INT2
35
25
36
P1.3/INT3
P1.3
INT3
36
26
37
P1.4/INT4
P1.4
INT4
37
27
38
P1.5/INT5
P1.5
INT5
38
28
39
P1.6/INT6
P1.6
INT6
39
29
40
P1.7/INT7
P1.7
INT7
10 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
PIN
BARE DIE
32 TQFNEP/LQFP
44 TQFNEP/TQFP
NAME
FUNCTION
Port 2 General-Purpose, Digital I/O Pins. These port pins function as
general-purpose I/O pins with their input and output states controlled by
the PD2, PO2, and PI2 registers. All port pins default to high-impedance
mode after a reset. Software must configure these pins after release
from reset to remove the high-impedance condition. All special functions must be enabled from software before they can be used.
GPIO PORT PIN
SPECIAL FUNCTION
P2.0/MOSI
P2.0
SPI: Master Out-Slave In
9
P2.1/MISO
P2.1
SPI: Master In-Slave Out
10
P2.2/SCLK
P2.2
SPI: Slave Clock
P2.3/SSEL
P2.4/TCK
P2.3
SPI: Active-Low Slave Select
29
P2.4
JTAG: Test Clock
19
30
P2.5/TDI
P2.5
JTAG: Test Data In
30
20
31
P2.6/TMS
P2.6
JTAG: Test Mode Select
31
21
32
P2.7/TDO
P2.7
JTAG: Test Data Out
9
—
8
10
—
11
—
12
—
11
28
18
29
Port 3 General-Purpose, Digital I/O Pins with Interrupt Capability. These
port pins function as general-purpose I/O pins with their input and output states controlled by the PD3, PO3, and PI3 registers. All port pins
default to high-impedance mode after a reset. Software must configure
these pins after release from reset to remove the high-impedance condition. All external interrupts must be enabled from software before they
can be used.
GPIO PORT PIN
EXTERNAL INTERRUPT
19
—
18
P3.0/INT8
P3.0
INT8
20
—
19
P3.1/INT9
P3.1
INT9
21
—
20
P3.2/INT10
P3.2
INT10
22
—
21
P3.3/INT11
P3.3
INT11
23
—
22
P3.4/INT12
P3.4
INT12
24
—
23
P3.5/INT13
P3.5
INT13
25
—
24
P3.6/INT14
P3.6
INT14
26
—
25
P3.7/INT15
P3.7
INT15
NO CONNECTION PINS
—
15, 16
26, 27
N.C.
No Connection. Not internally connected.
______________________________________________________________________________________ 11
MAXQ61C
Pin Description (continued)
MAXQ61C
16-Bit Microcontroller with Infrared Module
Block Diagram
MAXQ61C
REGULATOR
16-BIT MAXQ
RISC CPU
IR DRIVER
VOLTAGE
MONITOR
CLOCK
80KB
USER ROM
IR TIMER
GPIO
WATCHDOG
1.5KB
UTILITY ROM
SPI
2x
16-BIT TIMER
8kHz NANO
RING
2KB
DATA SRAM
USART X2
Detailed Description
The MAXQ61C provides integrated, low-cost solutions
that simplify the design of IR communications equipment such as universal remote controls. Standard features include the highly optimized, single-cycle, MAXQ,
16-bit RISC core; 80KB of user ROM memory; 2KB data
RAM; soft stack; 16 general-purpose registers; and
three data pointers. The MAXQ core has the industry’s
best MIPS/mA rating, allowing developers to achieve
the same performance as competing microcontrollers
at substantially lower clock rates. Lower active-mode
current combined with the even lower MAXQ61C stopmode current (0.2FA typ) results in increased battery
life. Application-specific peripherals include flexible
timers for generating IR carrier frequencies and modulation. A high-current IR drive pin capable of sinking up to
25mA current and output pins capable of sinking up to
5mA are ideal for IR applications. It also includes general-purpose I/O pins ideal for keypad matrix input, and
a power-fail-detection circuit to notify the application
when the supply voltage is nearing the microcontroller’s
minimum operating voltage.
At the heart of the device is the MAXQ 16-bit, RISC core.
Operating from DC to 12MHz, almost all instructions execute in a single clock cycle (83.3ns at 12MHz), enabling
nearly 12MIPS true-code operation. When active device
operation is not required, an ultra-low-power stop mode
can be invoked from software, resulting in quiescent
current consumption of less than 0.2FA (typ) and 2.0FA
(max). The combination of high-performance instructions
and ultra-low stop-mode current increases battery life
over competing microcontrollers. An integrated POR circuit with brownout support resets the device to a known
condition following a power-up cycle or brownout condition. Additionally, a power-fail warning flag is set, and a
power-fail interrupt can be generated when the system
voltage falls below the power-fail warning voltage, VPFW.
The power-fail warning feature allows the application to
notify the user that the system supply is low and appropriate action should be taken.
Microprocessor
The device is based on Maxim’s low-power, 16-bit MAXQ
family of RISC cores. The core supports the Harvard
memory architecture with separate 16-bit program and
data address buses. A fixed 16-bit instruction word is
standard, but data can be arranged in 8 or 16 bits. The
MAXQ core in the device is implemented as a pipelined processor with performance approaching 1MIPS
per MHz. The 16-bit data path is implemented around
register modules, and each register module contributes
specific functions to the core. The accumulator module
consists of sixteen 16-bit registers and is tightly coupled
with the arithmetic logic unit (ALU). A configurable soft
stack supports program flow.
Execution of instructions is triggered by data transfer
between functional register modules or between a functional register module and memory. Because data movement involves only source and destination modules,
circuit switching activities are limited to active modules
only. For power-conscious applications, this approach
localizes power dissipation and minimizes switching
noise. The modular architecture also provides a maximum of flexibility and reusability that are important for a
microprocessor used in embedded applications.
The MAXQ instruction set is highly orthogonal. All arithmetical and logical operations can use any register
in conjunction with the accumulator. Data movement
is supported from any register to any other register.
Memory is accessed through specific data-pointer registers with autoincrement/decrement support.
Memory
The microcontroller incorporates several memory types:
• 80KB user ROM
• 2KB SRAM data memory
• 1.5KB utility ROM
• Soft stack
12 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
The SP pointer indicates the current top of the stack,
which initializes by default to the top of the SRAM data
memory. As values are pushed onto the stack, the SP
pointer decrements, which means that the stack grows
downward towards the bottom (lowest address) of the
data memory. Popping values off the stack causes the
SP pointer value to increase. Refer to the MAXQ610
User’s Guide for more details.
Utility ROM
The utility ROM is a 1.5KB block of internal ROM memory
located in program space beginning at address 8000h.
This ROM includes the following routines:
• P
roduction test routines (internal memory tests,
memory loader, etc.), which are used for internal
testing only, and are generally of no use to the endapplication developer
• U
ser-callable routines for buffer copying and fast table
lookup (more information on these routines can be
found in the MAXQ610 User’s Guide)
Following any reset, execution begins in the utility ROM
at address 8000h. At this point, unless test mode has
been invoked (which requires special programming
through the JTAG interface), the utility ROM in the device
always automatically jumps to location 0000h, which is
the beginning of user application code.
Watchdog Timer
The internal watchdog timer greatly increases system
reliability. The timer resets the device if software execution is disturbed. The watchdog timer is a free-running
counter designed to be periodically reset by the application software. If software is operating correctly, the counter is periodically reset and never reaches its maximum
count. However, if software operation is interrupted,
the timer does not reset, triggering a system reset and
optionally a watchdog timer interrupt. This protects the
system against electrical noise or electrostatic discharge
(ESD) upsets that could cause uncontrolled processor
operation. The internal watchdog timer is an upgrade to
older designs with external watchdog devices, reducing
system cost and simultaneously increasing reliability.
The watchdog timer functions as the source of both the
watchdog timer timeout and the watchdog timer reset.
The timeout period can be programmed in a range of
215 to 224 system clock cycles. An interrupt is generated when the timeout period expires if the interrupt
is enabled. All watchdog timer resets follow the programmed interrupt timeouts by 512 system clock cycles.
If the watchdog timer is not restarted for another full
interval in this time period, a system reset occurs when
the reset timeout expires. See Table 1.
IR Carrier Generation
and Modulation Timer
The dedicated IR timer/counter module simplifies lowspeed infrared (IR) communication. The IR timer implements two pins (IRTX and IRRX) for supporting IR
transmit and receive, respectively. The IRTX pin has no
corresponding port pin designation, so the standard
PD, PO, and PI port control status bits are not present.
However, the IRTX pin output can be manipulated high
or low using the PWCN.IRTXOUT and PWCN.IRTXOE
bits when the IR timer is not enabled (i.e., IREN = 0).
Table 1. Watchdog Interrupt Timeout (Sysclk = 12MHz, CD[1:0] = 00)
WATCHDOG INTERRUPT TIMEOUT
WATCHDOG RESET AFTER
WATCHDOG INTERRUPT (μs)
Sysclk/215
2.7ms
42.7
01
Sysclk/218
21.9ms
42.7
10
Sysclk/221
174.7ms
42.7
11
Sysclk/224
1.4s
42.7
WD[1:0]
WATCHDOG CLOCK
00
______________________________________________________________________________________ 13
MAXQ61C
Stack Memory
The device provides a soft stack that can be used to
store program return addresses (for subroutine calls
and interrupt handling) and other general-purpose data.
This soft stack is located in the 2KB SRAM data memory, which means that the SRAM data memory must be
shared between the soft stack and general-purpose
application data storage. However, the location and
size of the soft stack is determined by the user, providing maximum flexibility when allocating resources for a
particular application. The stack is used automatically
by the processor when the CALL, RET, and RETI instructions are executed and when an interrupt is serviced. An
application can also store and retrieve values explicitly
using the stack by means of the PUSH, POP, and POPI
instructions.
MAXQ61C
16-Bit Microcontroller with Infrared Module
The IR timer is composed of a carrier generator and a
carrier modulator. The carrier generation module uses
the 16-bit IR carrier register (IRCA) to define the high
and low time of the carrier through the IR carrier high
byte (IRCAH) and IR carrier low byte (IRCAL). The carrier
modulator uses the IR data bit (IRDATA) and IR modulator time register (IRMT) to determine whether the carrier
or the idle condition is present on IRTX.
The IR timer is enabled when the IR enable bit (IREN) is
set to 1. The IR Value register (IRV) defines the beginning value for the carrier modulator. During transmission,
the IRV register is initially loaded with the IRMT value
and begins down counting towards 0000h, whereas
in receive mode it counts upward from the initial IRV
register value. During the receive operation, the IRV
register can be configured to reload with 0000h when
capture occurs on detection of selected edges or can be
allowed to continue free-running throughout the receive
operation. An overflow occurs when the IR timer value
rolls over from 0FFFFh to 0000h. The IR overflow flag
(IROV) is set to 1 and an interrupt is generated if enabled
(IRIE = 1).
Carrier Generation Module
The IRCAH byte defines the carrier high time in terms of
the number of IR input clocks, whereas the IRCAL byte
defines the carrier low time.
• IR Input Clock (fIRCLK) = fSYS/2IRDIV[1:0]
• C
arrier Frequency (fCARRIER) = fIRCLK/(IRCAH +
IRCAL + 2)
• Carrier High Time = IRCAH + 1
• Carrier Low Time = IRCAL + 1
• Carrier Duty Cycle = (IRCAH + 1)/(IRCAH + IRCAL + 2)
During transmission, the IRCA register is latched for
each IRV down-count interval, and is sampled along with
the IRTXPOL and IRDATA bits at the beginning of each
new IRV down-count interval so that duty-cycle variation
and frequency shifting is possible from one interval to the
next, which is illustrated in Figure 1.
Figure 2 illustrates the basic carrier generation and its
path to the IRTX output pin. The IR transmit polarity bit
(IRTXPOL) defines the starting/idle state and the carrier
polarity of the IRTX pin when the IR timer is enabled.
IR Transmission
During IR transmission (IRMODE = 1), the carrier generator creates the appropriate carrier waveform, while
the carrier modulator performs the modulation. The carrier modulation can be performed as a function of carrier
cycles or IRCLK cycles dependent on the setting of the
IRCFME bit. When IRCFME = 0, the IRV down counter is
clocked by the carrier frequency and thus the modulation is a function of carrier cycles. When IRCFME = 1, the
IRV down counter is clocked by IRCLK, allowing carrier
modulation timing with IRCLK resolution.
The IRTXPOL bit defines the starting/idle state as well as
the carrier polarity for the IRTX pin. If IRTXPOL = 1, the
IRTX pin is set to a logic-high when the IR timer module is
enabled. If IRTXPOL = 0, the IRTX pin is set to a logic-low
when the IR timer is enabled.
A separate register bit, IR data (IRDATA), is used to
determine whether the carrier generator output is output
to the IRTX pin for the next IRMT carrier cycles. When
IRDATA = 1, the carrier waveform (or inversion of this
waveform if IRTXPOL = 1) is output on the IRTX pin during the next IRMT cycles. When IRDATA = 0, the idle
condition, as defined by IRTXPOL, is output on the IRTX
pin during the next IRMT cycles.
The IR timer acts as a down counter in transmit mode. An
IR transmission starts when the IREN bit is set to 1 when
IRMODE = 1; when the IRMODE bit is set to 1 when IREN
= 1; or when IREN and IRMODE are both set to 1 in the
same instruction. The IRMT and IRCA registers, along
with the IRDATA and IRTXPOL bits, are sampled at the
beginning of the transmit process and every time the IR
timer value reload its value. When the IRV reaches 0000h
value, on the next carrier clock, it does the following:
1) Reloads IRV with IRMT.
2) Samples IRCA, IRDATA, and IRTXPOL.
3) Generates IRTX accordingly.
4) Sets IRIF to 1.
5) Generates an interrupt to the CPU if enabled (IRIE = 1).
To terminate the current transmission, the user can
switch to receive mode (IRMODE = 0) or clear IREN to 0.
Carrier Modulation Time = IRMT + 1 carrier cycles
14 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
IRCA = 0202h
IRCA = 0002h
IRMT
IRMT = 3
IRMT = 5
MAXQ61C
IRCA
IRCA, IRMT, IRDATA SAMPLED AT END OF IRV
DOWN-COUNT INTERVAL
3
2
1
0
5
4
3
2
1
0
CARRIER OUTPUT
(IRV)
IRDATA
0
1
0
IR INTERRUPT
IRTX
IRTXPOL = 1
IRTX
IRTXPOL = 0
Figure 1. IR Transmit Frequency Shifting Example (IRCFME = 0)
IRTXPOL
0
CARRIER GENERATION
IRCLK
IRTX PIN
1
CARRIER
IRCAH + 1
IRCAL + 1
IRCFME
0
1
IRDATA
IRMT
SAMPLE
IRDATA ON
IRV = 0000h
IR INTERRUPT
CARRIER MODULATION
Figure 2. IR Transmit Carrier Generation and Carrier Modulator Control
______________________________________________________________________________________ 15
MAXQ61C
16-Bit Microcontroller with Infrared Module
IR Transmit—Independent External Carrier
and Modulator Outputs
IRTXPOL = 0) on each IRV down-count interval boundary just as if it were being used to internally modulate
the carrier frequency. If IRTXPOL = 1, the inverse of
the IRDATA bit is output to the IRTXM pin on the IRV
interval down-count boundaries. See Figure 4. When
the envelope mode is enabled, it is possible to output
either the modulated (IRENV[1:0] = 01b) or unmodulated
(INENV[1:0] = 10b) carrier to the IRTX pin.
The normal transmit mode modulates the carrier based
upon the IRDATA bit. However, the user has the option
to input the modulator (envelope) on an external pin if
desired. If the IRENV[1:0] bits are configured to 01b or
10b, the modulator/envelope is output to the IRTXM pin.
The IRDATA bit is output directly to the IRTXM pin (if
IRMT = 3
CARRIER OUTPUT
(IRV)
3
2
1
0
3
2
1
0
IRDATA
0
1
0
IR INTERRUPT
IRTX
IRTXPOL = 1
IRTX
IRTXPOL = 0
Figure 3. IR Transmission Waveform (IRCFME = 0)
IRTXM
IRTXPOL = 1
IRTXM
IRTXPOL = 0
IRDATA
1
0
1
0
1
0
1
0
IR INTERRUPT
IRV INTERVAL
IRMT
IRMT
IRMT
Figure 4. External IRTXM (Modulator) Output
16 �������������������������������������������������������������������������������������
IRMT
16-Bit Microcontroller with Infrared Module
CARRIER MODULATION
IRCLK
IRCAH + 1
0
IRCAL + 1
IR TIMER OVERFLOW
1
IRCFME
INTERRUPT TO CPU
0000h
IRV
IR INTERRUPT
COPY IRV TO IRMT
ON EDGE DETECT
IRXRL
RESET IRV TO 0000h
IRRX PIN
EDGE DETECT
IRDATA
Figure 5. IR Capture
IR Receive
When configured in receive mode (IRMODE = 0), the
IR hardware supports the IRRX capture function. The
IRRXSEL[1:0] bits define which edge(s) of the IRRX pin
should trigger the IR timer capture function.
The IR module starts operating in the receive mode when
IRMODE = 0 and IREN = 1. Once started, the IR timer
(IRV) starts up counting from 0000h when a qualified
capture event as defined by IRRXSEL happens. The IRV
register is, by default, counting carrier cycles as defined
by the IRCA register. However, the IR carrier frequency
detect (IRCFME) bit can be set to 1 to allow clocking of
the IRV register directly with the IRCLK for finer resolution. When IRCFME = 0, the IRCA defined carrier is
counted by IRV. When IRCFME = 1, the IRCLK clocks
the IRV register.
On the next qualified event, the IR module does the
following:
1) C
aptures the IRRX pin state and transfers its value
to IRDATA. If a falling edge occurs, IRDATA = 0. If a
rising edge occurs, IRDATA = 1.
2) Transfers its current IRV value to the IRMT.
3) Resets IRV content to 0000h (if IRXRL = 1).
4) Continues counting again until the next qualified event.
If the IR timer value rolls over from 0FFFFh to 0000h
before a qualified event happens, the IR timer overflow
(IROV) flag is set to 1 and an interrupt is generated, if
enabled. The IR module continues to operate in receive
mode until it is stopped by switching into transmit mode
(IRMODE = 1) or clearing IREN = 0.
Carrier Burst-Count Mode
A special mode reduces the CPU processing burden
when performing IR learning functions. Typically, when
operating in an IR learning capacity, some number of
carrier cycles are examined for frequency determination. Once the frequency has been determined, the IR
receive function can be reduced to counting the number
of carrier pulses in the burst and the duration of the
combined mark-space time within the burst. To simplify
this process, the receive burst-count mode (as enabled
by the RXBCNT bit) can be used. When RXBCNT = 0,
the standard IR receive capture functionality is in place.
When RXBCNT = 1, the IRV capture operation is disabled and the interrupt flag associated with the capture
no longer denotes a capture. In the carrier burst-count
mode, the IRMT register only counts qualified edges.
The IRIF interrupt flag (normally used to signal a capture
when RXBCNT = 0) now becomes set if two IRCA cycles
elapse without getting a qualified edge. The IRIF interrupt flag thus denotes absence of the carrier and the
beginning of a space in the receive signal. When the
RXBCNT bit is changed from 0 to 1, the IRMT register
is set to 0001h. The IRCFME bit is still used to define
whether the IRV register is counting system IRCLK
clocks or IRCA-defined carrier cycles. The IRXRL bit
defines whether the IRV register is reloaded with 0000h
on detection of a qualified edge (per the IRXSEL[1:0]
bits). Figure 6 and the descriptive sequence embedded
in the figure illustrate the expected usage of the receive
burst-count mode.
______________________________________________________________________________________ 17
MAXQ61C
CARRIER GENERATION
MAXQ61C
16-Bit Microcontroller with Infrared Module
CARRIER FREQUENCY
CALCULATION
IRMT = PULSE COUNTING
IRV = CARRIER CYCLE COUNTING
IRMT = PULSE COUNTING
IRRX
IRV
IRMT
1
2
3
4
6
7
8
5
1 TO 4
9
CAPTURE INTERRUPT (IRIF = 1).
IRV ≥ IRMT.
IRV = 0 (IF IRXRL = 1).
5
SOFTWARE SETS IRCA = CARRIER FREQUENCY.
SOFTWARE SETS RXBCNT = 1 (WHICH CLEARS IRMT = 0001 IN HARDWARE).
SOFTWARE CLEARS IRCFME = 0 SO THAT IRV COUNTS CARRIER CYCLES. IRV IS RESET TO 0 ON QUALIFIED EDGE DETECTION IF IRXRL = 1.
SOFTWARE ADDS TO IRMT THE NUMBER OF PULSES USED FOR CARRIER MEASUREMENT.
IRCA x 2x COUNTER FOR SPACE CAN BEGIN IMMEDIATELY (QUALIFIED EDGE RESETS).
6
QUALIFIED EDGE DETECTED: IRMT++
IRV RESET TO 0 IF IRXRL = 1.
7
IRCA x 2 PERIOD ELAPSES: IRIF = 1; CARRIER ABSENCE = SPACE.
BURST MARK = IRMT PULSES.
SOFTWARE CLEARS RXBCNT = 0 SO THAT WE CAPTURE ON THE NEXT QUALIFIED EDGE.
8
9
QUALIFIED EDGE DETECTED: IRIF = 1, CAPTURE IRV IRMT AS THE BURST SPACE (PLUS UP TO ONE CARRIER CYCLE).
SOFTWARE SET RXBCNT = 1 AS IN (5).
CONTINUE (5) TO (8) UNTIL LEARNING SPACE EXCEEDS SOME DURATION. IRV ROLLOVERS CAN BE USED.
Figure 6. Receive Burst-Count Example
16-Bit Timers/Counters
• 16-bit timer with capture
The microcontroller provides two timers/counters that
support the following functions:
• 16-bit timer with compare
• 16-bit timer/counter
• Set/reset/toggle output state on comparator match
• 16-bit up/down autoreload
• Prescaler with 2n divider (for n = 0, 2, 4, 6, 8, 10)
• Input/output enhancements for pulse-width modulation
• Counter function of external pulse
18 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
The device provides two USART peripherals with the following features:
• 2-wire interface
• Full-duplex operation for asynchronous data transfers
• Half-duplex operation for synchronous data transfers
• P
rogrammable interrupt when transmit or receive data
operation completes
Serial Peripheral Interface (SPI)
The integrated SPI provides an independent serial
communication channel that communicates synchronously with peripheral devices in a multiple master or
multiple slave system. The interface allows access to
a 4-wire, full-duplex serial bus, and can be operated in
either master mode or slave mode. Collision detection
is provided when two or more masters attempt a data
transfer at the same time.
The maximum SPI master transfer rate is Sysclk/2. When
operating as an SPI slave, the device can support up to
Sysclk/4 SPI transfer rate. Data is transferred as an 8-bit
or 16-bit value, MSB first. In addition, the SPI module
supports configuration of an active SSEL state (active
low or active high) through the slave active select.
• Independent programmable baud-rate generator
• Optional 9th bit parity support
• Start/stop bit support
Table 2. USART Mode Details
MODE
TYPE
START BITS
DATA BITS
STOP BITS
Mode 0
Synchronous
N/A
8
N/A
Mode 1
Asynchronous
1
8
1
Mode 2
Asynchronous
1
8+1
1
Mode 3
Asynchronous
1
8+1
1
SHIFT
SAMPLE
SHIFT
SAMPLE
SSEL
SCLK
CKPOL/CKPHA
0/1 OR 1/0
tMCK
tMCH
tMCL
SCLK
CKPOL/CKPHA
0/0 OR 1/1
tMOH
tMOV
MSB
MOSI
MSB
tMLH
LSB
MSB-1
tMIS
MISO
tRF
tMIH
MSB-1
LSB
Figure 7. SPI Master Communication Timing
______________________________________________________________________________________ 19
MAXQ61C
USART
MAXQ61C
16-Bit Microcontroller with Infrared Module
SHIFT
SSEL
SAMPLE
SHIFT
SAMPLE
tSSH
tSSE
tSD
tSCK
SCLK
CKPOL/CKPHA
0/1 OR 1/0
tSCH
SCLK
CKPOL/CKPHA
0/0 OR 1/1
tSCL
tSIS
tSIH
MSB
MOSI
MSB-1
LSB
tSOV
MSB
MISO
tRF
tSLH
MSB-1
LSB
Figure 8. SPI Slave Communication Timing
General-Purpose I/O
VDD
The microcontroller provides port pins for general-purpose I/O that have the following features:
HFXIN
• CMOS output drivers
CLOCK CIRCUIT
STOP
• Schmitt trigger inputs
• O
ptional weak pullup to VDD when operating in input
mode
While the microcontroller is in a reset state, all port pins
become high impedance with both weak pullups and
input buffers disabled, unless otherwise noted.
From a software perspective, each port appears as a
group of peripheral registers with unique addresses.
Special function pins can also be used as general-purpose I/O pins when the special functions are disabled.
For a detailed description of the special functions available for each pin, refer to the MAXQ610 User’s Guide.
On-Chip Oscillator
An external quartz crystal or a ceramic resonator can be
connected between HFXIN and HFXOUT, as illustrated
in Figure 9.
RF
HFXOUT
C1
C2
RF = 1MI Q50%
C1 = C2 = 12pF
Figure 9. On-Chip Oscillator
Noise at HFXIN and HFXOUT can adversely affect onchip clock timing. It is good design practice to place the
crystal and capacitors near the oscillator circuitry and
connect HFXIN and HFXOUT to ground with a direct
short trace. The typical values of external capacitors vary
with the type of crystal to be used and should be initially
selected based on load capacitance as suggested by
the manufacturer.
20 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
The lowest power mode of operation is stop mode. In this
mode, CPU state and memories are preserved, but the
CPU is not actively running. Wake-up sources include
external I/O interrupts, the power-fail warning interrupt,
wake-up timer, or a power-fail reset. Any time the microcontroller is in a state where code does not need to be
executed, the user software can put the device into stop
mode. The nanopower ring oscillator is an internal ultralow-power (400nA) 8kHz ring oscillator that can be used
to drive a wake-up timer that exits stop mode. The wakeup timer is programmable by software in steps of 125Fs
up to approximately 8s.
The power-fail monitor is always on during normal operation. However, it can be selectively disabled during stop
mode to minimize power consumption. This feature is
enabled using the power-fail monitor disable (PFD) bit
in the PWCN register. The reset default state for the PFD
bit is 1, which disables the power-fail monitor function
during stop mode. If power-fail monitoring is disabled
(PFD = 1) during stop mode, the circuitry responsible
for generating a power-fail warning or reset is shut down
and neither condition is detected. Thus, the VDD < VRST
condition does not invoke a reset state.
VDD
t < tPFW
t ≥ tPFW
Power-Fail Detection
Figures 10, 11, and 12 show the power-fail detection and
response during normal and stop-mode operation. If a
reset is caused by a power-fail, the power-fail monitor
can be set to one of the following intervals:
• Always on—continuous monitoring
• 211 nanopower ring oscillator clocks (~256ms)
• 212 nanopower ring oscillator clocks (~512ms)
• 213 nanopower ring oscillator clocks (~1.024s)
In the case where the power-fail circuitry is periodically
turned on, the power-fail detection is turned on for two
nanopower ring-oscillator cycles. If VDD > VRST during
detection, VDD is monitored for an additional nanopower
ring-oscillator period. If VDD remains above VRST for
the third nanopower ring period, the CPU exits the reset
state and resumes normal operation from utility ROM at
8000h after satisfying the crystal warmup period.
If a reset is generated by any other event, such as the
RESET pin being driven low externally or the watchdog
timer, the power-fail, internal regulator, and crystal
remain on during the CPU reset. In these cases, the CPU
exits the reset state in less than 20 crystal cycles after
the reset source is removed.
t ≥ tPFW
t ≥ tPFW
C
VPFW
G
VRST
E
F
B
H
D
VPOR
I
A
INTERNAL RESET
(ACTIVE HIGH)
Figure 10. Power-Fail Detection During Normal Operation
______________________________________________________________________________________ 21
MAXQ61C
Operating Modes
MAXQ61C
16-Bit Microcontroller with Infrared Module
Table 3. Power-Fail Detection States During Normal Operation
STATE
POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
A
On
Off
Off
—
VDD < VPOR.
B
On
On
On
—
VPOR < VDD < VRST.
Crystal warmup time, tXTAL_RDY.
CPU held in reset.
C
On
On
On
—
VDD > VRST.
CPU normal operation.
D
On
On
On
—
Power drop too short.
Power-fail not detected.
—
VRST < VDD < VPFW.
PFI is set when VRST < VDD < VPFW and
maintains this state for at least tPFW, at
which time a power-fail interrupt is generated (if enabled).
CPU continues normal operation.
E
On
On
On
F
On
(Periodically)
Off
Off
Yes
G
On
On
On
—
H
On
(Periodically)
Off
Off
Yes
I
Off
Off
Off
—
COMMENTS
VPOR < VDD < VRST.
Power-fail detected.
CPU goes into reset.
Power-fail monitor turns on periodically.
VDD > VRST.
Crystal warmup time, tXTAL_RDY.
CPU resumes normal operation from 8000h.
VPOR < VDD < VRST.
Power-fail detected.
CPU goes into reset.
Power-fail monitor turns on periodically.
VDD < VPOR.
Device held in reset. No operation allowed.
22 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
t < tPFW
A
t ≥ tPFW
MAXQ61C
VDD
t ≥ tPFW
VPFW
D
VRST
B
C
E
VPOR
F
STOP
INTERNAL RESET
(ACTIVE HIGH)
Figure 11. Stop Mode Power-Fail Detection States with Power-Fail Monitor Enabled
Table 4. Stop Mode Power-Fail Detection States with Power-Fail Monitor Enabled
STATE
POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
A
On
Off
Off
Yes
Application enters stop mode.
VDD > VRST.
CPU in stop mode.
B
On
Off
Off
Yes
Power drop too short.
Power-fail not detected.
COMMENTS
C
On
On
On
Yes
VRST < VDD < VPFW.
Power-fail warning detected.
Turn on regulator and crystal.
Crystal warmup time, tXTAL_RDY.
Exit stop mode.
D
On
Off
Off
Yes
Application enters stop mode.
VDD > VRST.
CPU in stop mode.
E
On
(Periodically)
Off
Off
Yes
VPOR < VDD < VRST.
Power-fail detected.
CPU goes into reset.
Power-fail monitor turns on periodically.
F
Off
Off
Off
—
VDD < VPOR.
Device held in reset. No operation allowed.
______________________________________________________________________________________ 23
MAXQ61C
16-Bit Microcontroller with Infrared Module
VDD
A
D
VPFW
B
VRST
C
E
VPOR
F
STOP
INTERNAL RESET
(ACTIVE HIGH)
INTERRUPT
Figure 12. Stop Mode Power-Fail Detection with Power-Fail Monitor Disabled
Table 5. Stop Mode Power-Fail Detection States with Power-Fail Monitor Disabled
STATE
POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
A
Off
Off
Off
Yes
Application enters stop mode.
VDD > VRST.
CPU in stop mode.
B
Off
Off
Off
Yes
VDD < VPFW.
Power-fail not detected because power-fail
monitor is disabled.
Yes
VRST < VDD < VPFW.
An interrupt occurs that causes the CPU to
exit stop mode.
Power-fail monitor is turned on, detects a
power-fail warning, and sets the power-fail
interrupt flag.
Turn on regulator and crystal.
Crystal warmup time, tXTAL_RDY.
On stop mode exit, CPU vectors to the
higher priority of power-fail and the interrupt that causes stop mode exit.
C
On
On
On
COMMENTS
24 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
STATE
POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
D
Off
Off
Off
Yes
Application enters stop mode.
VDD > VRST.
CPU in stop mode.
COMMENTS
E
On
(Periodically)
Off
Off
Yes
VPOR < VDD < VRST.
An interrupt occurs that causes the CPU to
exit stop mode.
Power-fail monitor is turned on, detects a
power-fail, and puts CPU in reset.
Power-fail monitor is turned on periodically.
F
Off
Off
Off
—
VDD < VPOR.
Device held in reset. No operation allowed.
Applications Information
The low-power, high-performance RISC architecture of
this device makes it an excellent fit for many portable
or battery-powered applications. It is ideally suited for
applications such as universal remote controls that
require the cost-effective integration of IR transmit/
receive capability.
Grounds and Bypassing
purpose I/O pins. Negative voltage spikes on power pins
are especially problematic as they directly couple to the
internal power buses. Devices such as keypads can
conduct electrostatic discharges directly into the microcontroller and seriously damage the device. System
designers must protect components against these transients that can corrupt system memory.
Additional Documentation
Careful PCB layout significantly minimizes system-level
digital noise that could interact with the microcontroller
or peripheral components. The use of multilayer boards
is essential to allow the use of dedicated power planes.
The area under any digital components should be a continuous ground plane if possible. Keep bypass capacitor
leads short for best noise rejection and place the capacitors as close to the leads of the devices as possible.
Designers must have the following documents to fully
use all the features of this device. This data sheet
contains pin descriptions, feature overviews, and electrical specifications. Errata sheets contain deviations
from published specifications. The user’s guides offer
detailed information about device features and operation. The following documents can be downloaded from
www.maxim-ic.com/microcontrollers.
CMOS design guidelines for any semiconductor require
that no pin be taken above VDD or below GND. Violation
of this guideline can result in a hard failure (damage to
the silicon inside the device) or a soft failure (unintentional modification of memory contents). Voltage spikes
above or below the device’s absolute maximum ratings
can potentially cause a devastating IC latchup.
• T
his MAXQ61C data sheet, which contains electrical/
timing specifications, pin descriptions, and package
information.
Microcontrollers commonly experience negative voltage spikes through either their power pins or general-
• T
he MAXQ61C revision-specific errata sheet (www.maximic.com/errata).
• T
he MAXQ610 User’s Guide, which contains detailed
information on features and operation, including programming.
______________________________________________________________________________________ 25
MAXQ61C
Table 5. Stop Mode Power-Fail Detection States with Power-Fail Monitor Disabled
(continued)
MAXQ61C
16-Bit Microcontroller with Infrared Module
Development and
Technical Support
Deviations from the MAXQ610 User’s Guide
for the MAXQ61C
The MAXQ610 User’s Guide contains all the information that is needed to develop application code for the
MAXQ61C microcontroller. However, even though the
MAXQ610 and the MAXQ61C are largely code-compatible, there are certain differences between the two
devices that must be kept in mind when referring to the
MAXQ610 User’s Guide.
• T
he MAXQ61C is a ROM-only microcontroller, unlike
the MAXQ610, which contains programmable flash
program memory. Therefore, all sections in the
MAXQ610 User’s Guide relating to the flash controller,
the JTAG bootloader, and the debug engine should
be disregarded.
Maxim and third-party suppliers provide a variety of
highly versatile, affordably priced development tools for
this microcontroller, including the following:
• Compilers
• In-circuit emulators
• Integrated Development Environments (IDEs)
• S
erial-to-JTAG and USB-to-JTAG interface boards for
programming and debugging (for microcontrollers
with rewritable memory)
A partial list of development tool vendors can be found
at www.maxim-ic.com/MAXQ_tools.
• T
he following registers on the MAXQ610 (which are
described in the MAXQ610 User’s Guide) do not exist
on the MAXQ61C, and all references to them should
be disregarded:
For technical support, go to https://support.maxim-ic.
com/micro.
• Port 4 Output Register (PO4)
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
• Port 4 Direction Register (PD4)
• Port 4 Input Register (PI4)
Package Information
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
32 TQFN-EP
T3255+3
21-0140
32 LQFP
C32+2
21-0054
44 TQFN-EP
T4477+2
21-0144
44 TQFP
C44+2
21-0293
26 �������������������������������������������������������������������������������������
16-Bit Microcontroller with Infrared Module
REVISION
NUMBER
REVISION
DATE
0
4/10
DESCRIPTION
Initial release
PAGES
CHANGED
—
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010
Maxim Integrated Products 27
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAXQ61C
Revision History