Features • • • • • • • • • • • • • • 8 K × 8-bit EEPROM EEPROM Programmable Options Read Protection for the EEPROM Program Memory 256 × 4-bit RAM 2 × 32 × 16-bit Data EEPROM Up to Seven External/Internal Interrupt Sources Eight Hardware and Software Interrupt Priorities 16 Bi-directional I/Os Wide Supply-voltage Range (1.8V to 6.5V) Very Low Sleep Current (< 1 µA) Synchronous Serial Interface (2-wire, 3-wire) Multifunction Timer/Counter with Prescaler/Interval Timer Voltage Monitoring Inclusive Lo_BAT Detect Watchdog, POR and Brown-out Function 8k-flash Microcontroller ATAM894 1. Description The ATAM894 is a member of the Atmel’s family of 4-bit single chip microcontrollers with 8K × 8-bit EEPROM program memory. It is based on the 4-K MTP version ATAM893 and fully compatible with this MTP and the ROM versions ATAR090/890 and ATAR092/892. Figure 1-1. Block Diagram VSS VDD Brown-out protect. RESET Voltage monitor External input OSC1 OSC2 RC Crystal oscillators oscillators External clock input Clock management UTCM Timer 1 interval- and watchdog timer Timer 2 with prescaler VMI BP10 Port 1 BP13 EEPROM RAM 8 K x 8 bit 256 x 4 bit SD MARC4 Data direction BP22 Port 2 BP21 T2O Modulator 2 SSI BP20/NTE T2I Serial interface 4-bit CPU core I/O bus SC Modulator 3 Demodulator T3O Timer 3 timer/counter T3I BP23 Data direction + alternate function Data direction + interrupt control Data dir. + alt. function Port 4 Port 5 Port 6 BP40 BP42 BP52 BP50 T2O INT3 INT6 INT1 SC BP43 BP51 BP53 BP41 VMI INT3 INT6 INT1 T2I SD BP60 T3O EEPROM 2 x 32 x 16 bit SD SC BP63 T3I Rev. 4679D–4BMCU–05/05 2. Pin Configuration Figure 2-1. Table 2-1. 2 Pinning SSO24 Package NC 1 24 NC NC 2 23 NC VDD 3 22 VSS BP40/INT3/SC 4 21 BP43/INT3/SD BP53/INT1 5 20 BP42/T2O BP52/INT1 6 19 BP41/VMI/T2I BP51/INT6 7 18 BP23 BP50/INT6 8 17 BP22 OSC1 9 16 BP21 OSC2 10 15 BP20/NTE BP60/T3O 11 14 BP63/T3I BP10 12 13 BP13 Pin Description Pin Symbol Type Function Alternate Function Reset State 1 NC 2 NC – Not connected – – – Not connected – – 3 VDD – Supply voltage – NA 4 BP40 I/O Bi-directional I/O line of Port 4.0 SC-serial clock or INT3 external interrupt input Input 5 BP53 I/O Bi-directional I/O line of Port 5.3 INT1 external interrupt input Input 6 BP52 I/O Bi-directional I/O line of Port 5.2 INT1 external interrupt input Input 7 BP51 I/O Bi-directional I/O line of Port 5.1 INT6 external interrupt input Input 8 BP50 I/O Bi-directional I/O line of Port 5.0 INT6 external interrupt input Input 9 OSC1 I Oscillator input 4-MHz crystal input or 32-kHz crystal input or external Input clock input or external trimming resistor input 10 OSC2 O Oscillator output 4-MHz crystal output or 32-kHz crystal output or external clock input 11 BP60 I/O Bi-directional I/O line of Port 6.0 T3O Timer 3 output Input 12 BP10 I/O Bi-directional I/O line of Port 1.0 – Input 13 BP13 I/O Bi-directional I/O line of Port 1.3 – Input 14 BP63 I/O Bi-directional I/O line of Port 6.3 T3I Timer 3 input Input 15 BP20 I/O Bi-directional I/O line of Port 2.0 16 BP21 I/O Bi-directional I/O line of Port 2.1 – Input 17 BP22 I/O Bi-directional I/O line of Port 2.2 – Input 18 BP23 I/O Bi-directional I/O line of Port 2.3 – Input Input NTE test mode enable, see section ”Master Reset” on Input page 12 ATAM894 4679D–4BMCU–05/05 ATAM894 Table 2-1. Pin Description (Continued) Pin Symbol Type Function Alternate Function Reset State 19 BP41 I/O Bi-directional I/O line of Port 4.1 VMI voltage monitor input or T2I external clock input Timer 2 Input 20 BP42 I/O Bi-directional I/O line of Port 4.2 T2O Timer 2 output Input 21 BP43 I/O Bi-directional I/O line of Port 4.3 SD serial data I/O or INT3 external interrupt input Input 22 VSS – Circuit ground – Input 23 NC – Not connected – – 24 NC – Not connected – – 3. Introduction The ATAM894 is a member of Atmel’s family of 4-bit single-chip microcontrollers. Instead of ROM it contains EEPROM, RAM, parallel I/O ports, two 8-bit programmable multifunction timer/counters, voltage supervisor, interval timer with watchdog function and a sophisticated on-chip clock generation with integrated RC-, 32-kHz and 4-MHz crystal oscillators. 4. Differences Between ATAM894 and ATARx90/x92 4.1 Program Memory The program memory of the MTP device is realized as an EEPROM. The memory size for user programs is 8192 bytes. It is programmed as 258 × 32-byte blocks of data. The implemented LOCK bit function is user selectable and protects the device from unauthorized read out of the program memory. 4.2 Configuration Memory An additional area of 64 bytes of the EEPROM is used to store information about the hardware configuration. All the options that are selectable for the ROM versions are available to the user. This includes not only the different port options but also the possibilities to select different capacitors for OSC1 and OSC2, the option to enable or disable the hardlock for the watchdog, the option to select OSC2 instead of OSC1 as external clock input and the option to enable the external clock monitor as a reset source. Activating the options is performed by the reset circuitry. Reset starts a download sequence to transfer the information from the memory into a shift register (configuration register). 4.3 Data Memory The ATAM894 contains an internal data EEPROM that is organized as two pages of 32 × 16 bit. If it is necessary to be compatible with the ROM parts, only one page must be used with the flash part. Also for compatibility reasons the access to the EEPROM is handled via the MCL (serial interface) as in the corresponding ROM parts. A behavioral difference that only needs to be considered for error handling can be seen, when the communication via the MCL is not terminated correctly. A missing STOP condition leads to a significantly higher current consumption for the ROM parts compared to the flash parts. A slightly different concept for the read amplifiers of the memory makes the flash part more tolerant in terms of communication errors. 3 4679D–4BMCU–05/05 4.4 Reset Function During each reset (power-on or brown-out) the configuration register is reset and reloaded with the data from the configuration memory. This leads to a slightly different behavior compared to the ROM versions. Both devices switch their I/Os to input during reset but the ROM part has the mask selected pull-up or pull-down resistors active while the MTP has them removed until the download is finished. 5. MARC4 Architecture 5.1 General Description The MARC4 microcontroller consists of an advanced stack-based, 4-bit CPU core and on-chip peripherals. The CPU is based on the Harvard architecture with physically separate program memory (ROM) and data memory (RAM). Three independent buses, the instruction bus, the memory bus and the I/O bus, are used for parallel communication between ROM, RAM and peripherals. This enhances program execution speed by allowing both instruction prefetching, and a simultaneous communication to the on-chip peripheral circuitry. The extremely powerful integrated interrupt controller with associated eight prioritized interrupt levels supports fast and efficient processing of hardware events. The MARC4 is designed for the high-level programming language qFORTH. The core includes both, an expression and a return stack. This architecture enables high-level language programming without any loss of efficiency or code density. Figure 5-1. MARC4 Core MARC4 CORE Reset Program PC memory Reset Clock X Y SP RP Sleep 256 x 4-bit Instruction bus Memory bus Instruction decoder System clock RAM TOS CCR Interrupt controller ALU I/O bus On-chip peripheral modules 4 ATAM894 4679D–4BMCU–05/05 ATAM894 5.2 Components of MARC4 Core The core contains ROM, RAM, ALU, program counter, RAM address registers, instruction decoder and interrupt controller. The following sections describe each functional block in more detail. 5.2.1 Program Memory The program memory (EEPROM) is electrically programmable and erasable with the customer application program. The program memory is addressed by a 12-bit wide program counter and an additional ROM bank register, thus predefining a maximum linear adressable program bank size of 4 Kbytes. The upper 2 Kbytes may be exchanged by ROM banking, thus allowing to address a maximum of 10 Kbytes user program. 8 Kbytes of program memory are available within the ATAM894. The lowest user (EEP)ROM address segment is taken up by a 512-byte zero page which contains predefined start addresses for interrupt service routines and special subroutines accessible with single byte instructions (SCALL). The corresponding memory map is shown in Figure 5-2. Look-up tables of constants can also be held in ROM and are accessed via the MARC4’s built-in table instruction. Figure 5-2. ROM Map Bank 4 Port D: 11xxb Bank 3 1FFh 1F8 h 1 F0 h 1E8h 1E0h Port D: 10xxb SCALL addresses Bank 2 FFFh Port D: 01xxb Bank 1 Port D: 00xxb 800h 7FFh Base bank Zero page 000h 5.2.1.1 5.2.2 000h 020h 01 8 h 01 0 h 008h 000h page 1E0h INT7 1C 0h INT6 1 8 0h INT5 1 4 0h INT4 100h INT3 0C 0h INT2 080h INT1 0 4 0h INT0 0 0 8h 000h $AUTOSLEEP $RESET ROM Banking For customers programming with qFORTH the bank switching is fully supported by the compiler. The MARC4 switches from one ROM bank to another by writing the new bank number to the ROM Bank Register (RBR). Conventional program space (power-up bank) resides in ROM bank 0. Each ROM bank consists of a 2 Kbyte address space whereby the lowest 2 Kbyte, the base bank, is common to all banks, so that addresses between 000h and 7FFh always access the same ROM data (see Figure 5-2). When ROM banking is used, the compiler will, if necessary, insert program code to save and restore the condition of the RBR on bank switching. RAM The ATAM894 contains 256 × 4-bit wide static random access memory (RAM). It is used for the expression stack, the return stack and data memory for variables and arrays. The RAM is addressed by any of the four 8-bit wide RAM address registers SP, RP, X and Y. 5 4679D–4BMCU–05/05 5.2.2.1 Expression Stack The 4-bit wide expression stack is addressed with the expression Stack Pointer (SP). All arithmetic, I/O and memory reference operations take their operands from, and return their results to the expression stack. The MARC4 performs the operations with the top of stack items (TOS and TOS-1). The TOS register contains the top element of the expression stack and works in the same way as an accumulator. This stack is also used for passing parameters between subroutines and as a scratch pad area for temporary storage of data. 5.2.2.2 Return Stack The 12-bit wide return stack is addressed by the Return stack Pointer (RP). It is used for storing return addresses of subroutines, interrupt routines and for keeping loop index counts. The return stack can also be used as a temporary storage area. The MARC4 instruction set supports the exchange of data between the top elements of the expression stack and the return stack. The two stacks within the RAM have a user definable location and maximum depth. Figure 5-3. RAM Map RAM (256 x 4-bit) Expression stack Autosleep RAM address register: 0 TOS TOS-1 TOS-2 Global variables X SP 4-bit Y SP TOS-1 Expression stack Return stack 11 0 RP Return stack RP 04h 00h 5.2.3 3 FFh FCh 07h 03h Global vvariables 12-bit Registers The MARC4 controller has seven programmable registers and one condition code register. They are shown in the following programming model. 5.2.3.1 6 Program Counter (PC) The program counter is a 12-bit register which contains the address of the next instruction to be fetched from the ROM. Instructions currently being executed are decoded in the instruction decoder to determine the internal micro-operations. For linear code (no calls or branches) the program counter is incremented with every instruction cycle. If a branch-, call-, return-instruction or an interrupt is executed, the program counter is loaded with a new address. The program counter is also used with the table instruction to fetch 8-bit wide ROM constants. ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 5-4. Programming Model 11 0 PC Program counter 3 0 -- RBR -- ROM banking register 0 7 0 RP 0 Return stack pointer 0 7 SP Expression stack pointer 0 7 X RAM address register (X) 7 0 Y RAM address register (Y) 3 0 3 0 Top of stack register TOS CCR C -- B I Condition code register Interrupt enable Branch Reserved Carry/borrow 5.2.3.2 ROM Banking Register (RBR) The ROM banking register is a 4-bit register whereby the ATAM894 only uses 2 bit. This register indicates which ROM bank is presently being addressed. The RBR is accessed with a standard qFORTH peripheral read or write instruction (IN or OUT, port address 'D' hex). 5.2.3.3 RAM Address Registers The RAM is addressed with the four 8-bit wide RAM address registers: SP, RP, X and Y. These registers allow access to any of the 256 RAM nibbles. 5.2.3.4 Expression Stack Pointer (SP) The stack pointer contains the address of the next-to-top 4-bit item (TOS-1) of the expression stack. The pointer is automatically pre-incremented if a nibble is moved onto the stack or postdecremented if a nibble is removed from the stack. Every post-decrement operation moves the item (TOS-1) to the TOS register before the SP is decremented. After a reset the stack pointer has to be initialized with “>SP S0” to allocate the start address of the expression stack area. 5.2.3.5 Return Stack Pointer (RP) The return stack pointer points to the top element of the 12-bit wide return stack. The pointer automatically pre-increments if an element is moved onto the stack, or it post-decrements if an element is removed from the stack. The return stack pointer increments and decrements in steps of 4. This means that every time a 12-bit element is stacked, a 4-bit RAM location is left unwritten. This location is used by the qFORTH compiler to allocate 4-bit variables. After a reset the return stack pointer has to be initialized via “>RP FCh”. 7 4679D–4BMCU–05/05 5.2.3.6 RAM Address Registers (X and Y) The X and Y registers are used to address any 4-bit item in the RAM. A fetch operation moves the addressed nibble onto the TOS. A store operation moves the TOS to the addressed RAM location. By using either the pre-increment or post-decrement addressing mode arrays in the RAM can be compared, filled or moved. 5.2.3.7 Top Of Stack (TOS) The top of stack register is the accumulator of the MARC4. All arithmetic/logic, memory reference and I/O operations use this register. The TOS register receives data from the ALU, ROM, RAM or I/O bus. 5.2.3.8 Condition Code Register (CCR) The 4-bit wide condition code register contains the branch, the carry and the interrupt enable flag. These bits indicate the current state of the CPU. The CCR flags are set or reset by ALU operations. The instructions SET_BCF, TOG_BF, CCR! and DI allow direct manipulation of the condition code register. 5.2.3.9 Carry/Borrow (C) The carry/borrow flag indicates that the borrowing or carrying out of Arithmetic Logic Unit (ALU) occurred during the last arithmetic operation. During shift and rotate operations, this bit is used as a fifth bit. Boolean operations have no affect on the C-flag. 5.2.3.10 Branch (B) The branch flag controls the conditional program branching. Should the branch flag have been set by a previous instruction, a conditional branch will cause a jump. This flag is affected by arithmetic, logic, shift, and rotate operations. 5.2.3.11 5.2.4 Interrupt Enable (I) The interrupt enable flag globally enables or disables the triggering of all interrupt routines with the exception of the non-maskable reset. After a reset or on executing the DI instruction, the interrupt enable flag is reset, thus disabling all interrupts. The core will not accept any further interrupt requests until the interrupt enable flag has been set again by either executing an EI or SLEEP instruction. ALU The 4-bit ALU performs all the arithmetic, logical, shift and rotate operations with the top two elements of the expression stack (TOS and TOS-1) and returns the result to the TOS. The ALU operations affect the carry/borrow and branch flag in the condition code register (CCR). 8 ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 5-5. ALU Zero-address Operations RAM SP TOS-1 TOS TOS-2 TOS-3 TOS-4 ALU CCR 5.2.5 I/O Bus The I/O ports and the registers of the peripheral modules are I/O mapped. All communication between the core and the on-chip peripherals takes place via the I/O bus and the associated I/O control. With the MARC4 IN and OUT instructions the I/O bus allows a direct read or write access to one of the 16 primary I/O addresses. More about the I/O access to the on-chip peripherals is described in the section ”Peripheral Modules” on page 22. The I/O bus is internal and is not accessible by the customer on the final microcontroller device, but it is used as the interface for the MARC4 emulation (see section ”Emulation” on page 92). 5.2.6 Instruction Set The MARC4 instruction set is optimized for the high level programming language qFORTH. Many MARC4 instructions are qFORTH words. This enables the compiler to generate a fast and compact program code. The CPU has an instruction pipeline allowing the controller to prefetch an instruction from program memory at the same time as the present instruction is being executed. The MARC4 is a zero address machine, the instructions containing only the operation to be performed and no source or destination address fields. The operations are implicitly performed on the data placed on the stack. There are one and two byte instructions which are executed within 1 to 4 machine cycles. A MARC4 machine cycle is made up of two system clock cycles (SYSCL). Most of the instructions are only one byte long and are executed in a single machine cycle. For more information refer to the “MARC4 Programmer’s Guide”. 5.2.7 Interrupt Structure The MARC4 can handle interrupts with eight different priority levels. They can be generated from the internal and external interrupt sources or by a software interrupt from the CPU itself. Each interrupt level has a hard-wired priority and an associated vector for the service routine in the program memory (see Table 5-1 on page 11). The programmer can postpone the processing of interrupts by resetting the interrupt enable flag (I) in the CCR. An interrupt occurrence will still be registered, but the interrupt routine only started after the I flag is set. All interrupts can be masked, and the priority individually software configured by programming the appropriate control register of the interrupting module (see section ”Peripheral Modules” on page 22). 9 4679D–4BMCU–05/05 5.2.8 Interrupt Processing For processing the eight interrupt levels, the MARC4 includes an interrupt controller with two 8-bit wide “interrupt pending” and “interrupt active” registers. The interrupt controller samples all interrupt requests during every non-I/O instruction cycle and latches these in the interrupt pending register. If no higher priority interrupt is present in the interrupt active register, it signals the CPU to interrupt the current program execution. If the interrupt enable bit is set, the processor enters an interrupt acknowledge cycle. During this cycle a short call (SCALL) instruction to the service routine is executed and the current PC is saved on the return stack. An interrupt service routine is completed with the RTI instruction. This instruction resets the corresponding bits in the interrupt pending/active register and fetches the return address from the return stack to the program counter. When the interrupt enable flag is reset (triggering of interrupt routines are disabled), the execution of new interrupt service routines is inhibited but not the logging of the interrupt requests in the interrupt pending register. The execution of the interrupt is delayed until the interrupt enable flag is set again. Note that interrupts are only lost if an interrupt request occurs while the corresponding bit in the pending register is still set (i.e., the interrupt service routine is not yet finished). 5.2.9 Interrupt Latency The interrupt latency is the time from the occurrence of the interrupt to the interrupt service routine being activated. In MARC4 this is extremely short (taking between 3 to 5 machine cycles depending on the state of the core). Figure 5-6. Interrupt Handling INT7 7 INT7 active Priority Level RTI INT5 6 5 INT5 active RTI INT3 4 INT2 3 INT3 active RTI 2 INT2 pending INT2 active RTI 1 SWI0 0 INT0 pending INT0 active RTI Main / Autosleep Main/ Autosleep Time 10 ATAM894 4679D–4BMCU–05/05 ATAM894 Interrupt Priority Table Table 5-1. Interrupt Priority ROM Address Interrupt Opcode Function INT0 Lowest 040h C8h (SCALL 040h) Software interrupt (SWI0) INT1 | 080h D0h (SCALL 080h) External hardware interrupt, any edge at BP52 or BP53 INT2 | 0C0h D8h (SCALL 0C0h) Timer 1 interrupt INT3 | 100h E8h (SCALL 100h) SSI interrupt or external hardware interrupt at BP40 or BP43 INT4 | 140h E8h (SCALL 140h) Timer 2 interrupt INT5 | 180h F0h (SCALL 180h) Timer 3 interrupt INT6 ↓ 1C0h F8h (SCALL 1C0h) External hardware interrupt, at any edge at BP50 or BP51 INT7 Highest 1E0h FCh (SCALL 1E0h) Voltage Monitor (VM) interrupt Hardware Interrupts Table 5-2. Interrupt Mask Interrupt Register Bit Interrupt Source INT1 P5CR P52M1, P52M2 P53M1, P53M2 Any edge at BP52 Any edge at BP53 INT2 T1M T1IM Timer 1 INT3 SISC SIM SSI buffer full/empty or BP40/BP43 interrupt INT4 T2CM T2IM Timer 2 compare match/overflow INT5 T3CM1 T3CM2 T3C T3IM1 T3IM2 T3EIM Timer 3 compare register 1 match Timer 3 compare register 2 match Timer 3 edge event occurs (T3I) INT6 P5CR P50M1, P50M2 P51M1, P51M2 INT7 VCM VIM Any edge at BP50 Any edge at BP51 External/internal voltage monitoring 5.2.9.1 Software Interrupts The programmer can generate interrupts by using the software interrupt instruction (SWI) which is supported in qFORTH by predefined macros named SWI0 to SWI7. The software triggered interrupt operates exactly like any hardware triggered interrupt. The SWI instruction takes the top two elements from the expression stack and writes the corresponding bits via the I/O bus to the interrupt pending register. Therefore, by using the SWI instruction, interrupts can be re-prioritized or lower priority processes scheduled for later execution. 5.2.9.2 Hardware Interrupts In the ATAM894, there are eleven hardware interrupt sources with seven different levels. Each source can be masked individually by mask bits in the corresponding control registers. An overview of the possible hardware configurations is shown in Table 5-2 on page 11. 11 4679D–4BMCU–05/05 5.3 Master Reset The master reset forces the CPU into a well-defined condition. It is unmaskable and is activated independent of the current program state. It can be triggered by either initial supply power-up, a short collapse of the power supply, brown-out detection circuitry, watchdog time-out, or an external input clock supervisor stage (see Figure 5-7 on page 12). A master reset activation will reset the interrupt enable flag, the interrupt pending register and the interrupt active register. During the power-on reset phase the I/O bus control signals are set to reset mode thereby initializing all on-chip peripherals. All bi-directional ports are set to input mode. Attention: During any reset phase, the BP20/NTE input is driven towards VDD by a strong pullup transistor. This pin must not be pulled down to VSS during reset by any external circuitry representing a resistor of less than 150 kΩ. Releasing the reset results in a short call instruction (opcode C1h) to the EEPROM address 008h. This activates the initialization routine $RESET which in turn has to initialize all necessary RAM variables, stack pointers and peripheral configuration registers (see Table 6-1 on page 23). Figure 5-7. Reset Configuration VDD Pull-up CL NRST res Reset timer Internal reset CL = SYSCL/4 5.3.1 Power-on reset VDD Brown-out detection VDD VSS VSS Watchres dog CWD Ext. clock supervisor ExIn Power-on Reset and Brown-out Detection The ATAM894 has a fully integrated power-on reset and brown-out detection circuitry. For reset generation no external components are needed. These circuits ensure that the core is held in the reset state until the minimum operating supply voltage has been reached. A reset condition will also be generated should the supply voltage drop momentarily below the minimum operating level except when a power down mode is activated (the core is in SLEEP mode and the peripheral clock is stopped). In this power-down mode the brown-out detection is disabled. Two values for the brown-out voltage threshold are programmable via the BOT bit in the SC register. 12 ATAM894 4679D–4BMCU–05/05 ATAM894 A power-on reset pulse is generated by a VDD rise across the default BOT voltage level (1.7V). A brown-out reset pulse is generated when VDD falls below the brown-out voltage threshold. Two values for the brown-out voltage threshold are programmable via the BOT bit in the SC register. When the controller runs in the upper supply voltage range with a high system clock frequency, the high threshold must be used. When it runs with a lower system clock frequency, the low threshold and a wider supply voltage range may be chosen. For further details, see the electrical specification and the SC register description for BOT programming. Figure 5-8. Brown-out Detection VDD 2.0 V 1.7 V td CPU Reset t BOT = 1 td CPU Reset td BOT = 0 td = 1.5 ms (typically) Note: BOT = 1, low brown-out voltage threshold 1.7V (is reset value). BOT = 0, high brown-out voltage threshold 2.0V. 5.3.2 Watchdog Reset The watchdog's function can be enabled at the WDC register and triggers a reset with every watchdog counter overflow. To suppress the watchdog reset, the watchdog counter must be regularly reset by reading the watchdog register address (CWD). The CPU reacts in exactly the same manner as a reset stimulus from any of the above sources. 5.3.3 External Clock Supervisor The external input clock supervisor function can be enabled if the external input clock is selected within the CM- and SC registers of the clock module. The CPU reacts in exactly the same manner as a reset stimulus from any of the above sources. 5.4 Voltage Monitor The voltage monitor consists of a comparator with an internal voltage reference. It is used to supervise the supply voltage or an external voltage at the VMI pin. The comparator for the supply voltage has three internal programmable thresholds: one lower threshold (2.2V), one middle threshold (2.6 V) and one higher threshold (3.0V). For external voltages at the VMI pin, the comparator threshold is set to VBG = 1.3V. The VMS bit indicates if the supervised voltage is below (VMS = 0) or above (VMS = 1) this threshold. An interrupt can be generated when the VMS bit is set or reset to detect a rising or falling slope. A voltage monitor interrupt (INT7) is enabled when the interrupt mask bit (VIM) is reset in the VMC register. 13 4679D–4BMCU–05/05 Voltage Monitor Figure 5-9. VDD Voltage monitor BP41/ VMI VMC: VM2 VM1 VMST: 5.4.1 INT7 OUT IN - VM0 - VIM res VMS Voltage Monitor Control/ Status Register Primary register address: ’F’hex Bit 3 Bit 2 Bit 1 Bit 0 VMC: Write VM2 VM1 VM0 VIM Reset value: 1111b VMST: Read – – reserved VMS Reset value: xx11b VM2: Voltage monitor Mode bit 2 VM1: Voltage monitor Mode bit 1 VM0: Voltage monitor Mode bit 0 Table 5-3. 14 Voltage Monitor Modes VM2 VM1 VM0 Function 1 1 1 Disable voltage monitor 1 1 0 External (VIM input), internal reference threshold (1.3V), interrupt with negative slope 1 0 1 Not allowed 1 0 0 External (VMI input), internal reference threshold (1.3V), interrupt with positive slope 0 1 1 Internal (supply voltage), high threshold (3.0V), interrupt with negative slope 0 1 0 Internal (supply voltage), middle threshold (2.6V), interrupt with negative slope 0 0 1 Internal (supply voltage), low threshold (2.2V), interrupt with negative slope 0 0 0 Not allowed ATAM894 4679D–4BMCU–05/05 ATAM894 Voltage Interrupt Mask bit VIM VIM = 0, voltage monitor interrupt is enabled VIM = 1, voltage monitor interrupt is disabled Voltage Monitor Status bit VMS VMS = 0, the voltage at the comparator input is below VRef VMS = 1, the voltage at the comparator input is above VRef Figure 5-10. Internal Supply Voltage Supervisor VMS = 1 VDD Low threshold Middle threshold High threshold 3.0 V 2.6 V 2.2 V Low threshold Middle threshold High threshold VMS = 0 Figure 5-11. External Input Voltage Supervisor Internal reference level VMI Negative slope Interrupt positive slope VMS = 1 VMS = 1 VMS = 0 VMS = 0 1.3 V Positive slope Interrupt negative slope 5.5 5.5.1 t Clock Generation Clock Module The ATAM894 contains a clock module with 4 different internal oscillator types: two RC-oscillators, one 4-MHz crystal oscillator and one 32-kHz crystal oscillator. The pins OSC1 and OSC2 are the interface to connect a crystal either to the 4-MHz, or to the 32-kHz crystal oscillator. OSC1 can be used as input for external clocks or to connect an external trimming resistor for the RC-oscillator 2. All necessary circuitry except the crystal and the trimming resistor is integrated on-chip. One of these oscillator types or an external input clock can be selected to generate the system clock (SYSCL). In applications that do not require exact timing, it is possible to use the fully integrated RC-oscillator 1 without any external components. The RC-oscillator 1 center frequency tolerance is better than ±50%. The RC-oscillator 2 is a trimmable oscillator whereby the oscillator frequency can be trimmed with an external resistor attached between OSC1 and VDD. In this configuration, the RC-oscillator 2 frequency can be maintained stable to within a tolerance of ±15% over the full operating temperature and voltage range. 15 4679D–4BMCU–05/05 The clock module is programmable via software with the clock management register (CM) and the system configuration register (SC). The required oscillator configuration can be selected with the OS1 bit and the OS0 bit in the SC register. A programmable 4-bit divider stage allows the adjustment of the system clock speed. A special feature of the clock management is that an external oscillator may be used and switched on and off via a port pin for the power-down mode. Before the external clock is switched off, the internal RC-oscillator 1 must be selected with the CCS bit and then the SLEEP mode may be activated. In this state an interrupt can wake up the controller with the RC-oscillator, and the external oscillator can be activated and selected by software. A synchronization stage avoids clock periods that are too short if the clock source or the clock speed is changed. If an external input clock is selected, a supervisor circuit monitors the external input and generates a hardware reset if the external clock source fails or drops below 500 kHz for more than 1 ms. Figure 5-12. Clock Module RCoscillator 1 Ext. clock OSC1 Oscin SYSCL ExOut Stop ExIn * RC-oscillator 2 Stop RCOut2 Stop R Trim RCOut1 Control IN1 Cin /2 /2 4-MHz oscillator Oscin Oscout /2 /2 IN2 Divider 4Out Stop 32-kHz oscillator OSC2 Oscout * Oscin Oscout 32Out Osc-Stop CM: Sleep WDL Cin/16 NSTOP CCS CSS1 SUBCL CSS0 32 kHz * configurable SC: BOT --- OS1 OS0 Clock Modes Table 5-4. Clock Source for SYSCL Mode OS1 OS0 CCS = 1 CCS = 0 Clock Source for SUBCL 1 1 1 RC-oscillator 1 (intern) External input clock Cin/16 2 0 1 RC-oscillator 1 (intern) RC-oscillator 2 with external trimming resistor Cin/16 3 1 0 RC-oscillator 1 (intern) 4-MHz oscillator Cin/16 4 0 0 RC-oscillator 1 (intern) 32-kHz oscillator 32 kHz The clock module generates two output clocks. One is the system clock (SYSCL) and the other the periphery (SUBCL). The SYSCL can supply the core and the peripherals and the SUBCL can supply only the peripherals with clocks. The modes for clock sources are programmable with the OS1 bit and OS0 bit in the SC register and the CCS bit in the CM register. 16 ATAM894 4679D–4BMCU–05/05 ATAM894 5.5.2 5.5.2.1 Oscillator Circuits and External Clock Input Stage The ATAM894 series consists of four different internal oscillators: two RC-oscillators, one 4-MHz crystal oscillator, one 32-kHz crystal oscillator and one external clock input stage. RC-oscillator 1 Fully Integrated For timing insensitive applications, it is possible to use the fully integrated RC-oscillator 1. It operates without any external components and saves additional costs. The RC-oscillator 1 center frequency tolerance is better than ±50% over the full temperature and voltage range. The basic center frequency of the RC-oscillator 1 is fO ≈ 4.0 MHz. The RC-oscillator 1 is selected by default after power-on reset. Figure 5-13. RC-oscillator 1 RC-oscillator 1 RcOut1 RcOut1 Osc-Stop Stop Control 5.5.2.2 External Input Clock The OSC1 or OSC2 can be driven by an external clock source provided it meets the specified duty cycle, rise and fall times and input levels. Additionally, the external clock stage contains a supervisory circuit for the input clock. The supervisor function is controlled via the OS1, OS0 bit in the SC register and the CCS bit in the CM register. If the external input clock is missing for more than 1 ms and CCS = 0 is set in the CM register, the supervisory circuit generates a hardware reset. Figure 5-14. External Input Clock Ext. input clock Ext. Clock ExOut OSC1 ExIn Stop or Ext. Clock RcOut1 Osc-Stop CCS OSC2 Clock monitor Res 17 4679D–4BMCU–05/05 Table 5-5. 5.5.2.3 Supervisor Function Control Bits OS1 OS0 CCS Supervisor Reset Output (Res) 1 1 0 Enable 1 1 1 Disable x 0 x Disable RC-oscillator 2 with External Trimming Resistor The RC-oscillator 2 is a high resolution trimmable oscillator whereby the oscillator frequency can be trimmed with an external resistor between OSC1 and VDD. In this configuration, the RC-oscillator 2 frequency can be maintained stable with a tolerance of ±15% over the full operating temperature and a voltage range VDD from 2.5V to 6.0V. For example: An output frequency at the RC-oscillator 2 of 2 MHz can be obtained by connecting a resistor Rext = 360 kΩ (see Figure 5-15). Figure 5-15. RC-oscillator 2 VDD RC-oscillator 2 Rext OSC1 RcOut2 RcOut2 RTrim Osc-Stop Stop OSC2 5.5.2.4 4-MHz Oscillator The ATAM894 4-MHz oscillator options need a crystal or ceramic resonator connected to the OSC1 and OSC2 pins to establish oscillation. All the necessary oscillator circuitry, with the exception of the actual crystal, resonator, C3 and C4 are integrated on-chip. Figure 5-16. 4-MHz Crystal Oscillator OSC1 Oscin 4Out * XTAL 4 MHz C1 4-MHz oscillator Oscout OSC2 Stop 4Out Osc-Stop * * C2 configurable Note: 18 Both, the 4-MHz and the 32-kHz crystal oscillator, use an integrated 14 stage divider circuit to stabilize oscillation before the oscillator output is used as system clock. This results in an additional delay of about 4 ms for the 4-MHz crystal and about 500 ms for the 32-kHz crystal. ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 5-17. Ceramic Resonator C3 OSC1 Oscin 4Out * Cer. Res 4-MHz oscillator C1 Oscout OSC2 C4 Stop 4Out Osc-Stop * * C2 configurable Note: 5.5.2.5 Both, the 4-MHz and the 32-kHz crystal oscillator, use an integrated 14 stage divider circuit to stabilize oscillation before the oscillator output is used as system clock. This results in an additional delay of about 4 ms for the 4-MHz crystal and about 500 ms for the 32-kHz crystal. 32-kHz Oscillator Some applications require long-term time keeping or low resolution timing. In this case, an on-chip, low power 32-kHz crystal oscillator can be used to generate both the SUBCL and the SYSCL. In this mode, power consumption is greatly reduced. The 32-kHz crystal oscillator can not be stopped while the power-down mode is in operation. Figure 5-18. 32-kHz Crystal Oscillator OSC1 Oscin 32Out * XTAL 32 kHz C1 32Out 32-kHz oscillator Oscout OSC2 * * C2 configurable Note: 5.5.3 Both, the 4-MHz and the 32-kHz crystal oscillator, use an integrated 14 stage divider circuit to stabilize oscillation before the oscillator output is used as system clock. This results in an additional delay of about 4 ms for the 4-MHz crystal and about 500 ms for the 32-kHz crystal. Clock Management The clock management register controls the system clock divider and synchronization stage. Writing to this register triggers the synchronization cycle. 19 4679D–4BMCU–05/05 5.5.3.1 Clock Management Register (CM) Auxiliary register address: '3'hex CM: Bit 2 Bit 1 Bit 0 NSTOP CCS CSS1 CSS0 Reset value: 1111b NSTOP Not STOP peripheral clock NSTOP = 0, stops the peripheral clock while the core is in SLEEP mode NSTOP = 1, enables the peripheral clock while the core is in SLEEP mode CCS Core Clock Select CCS = 1, the internal RC-oscillator 1 generates SYSCL CCS = 0, the 4-MHz crystal oscillator, the 32-kHz crystal oscillator, an external clock source or the RC-oscillator 2 with the external resistor at OSC1 generates SYSCL dependent on the setting of OS0 and OS1 in the system configuration register CSS1 Core Speed Select 1 CSS0 Core Speed Select 0 Core Speed Select Table 5-6. 5.5.3.2 Bit 3 CSS1 CSS0 Divider 0 0 16 1 1 8 1 0 4 0 1 2 Note Reset value System Configuration Register (SC) Primary register address: '3'hex 20 Bit 3 Bit 2 Bit 1 Bit 0 SC: write BOT – OS1 OS0 BOT Brown-Out Threshold BOT = 1, low brown-out voltage threshold (1.65V) BOT = 0, high brown-out voltage threshold (1.95V) OS1 Oscillator Select 1 OS0 Oscillator Select 0 Reset value: 1x11b ATAM894 4679D–4BMCU–05/05 ATAM894 Oscillator Select Table 5-7. Mode OS1 OS0 Input for SUBCL 1 1 1 Cin/16 RC-oscillator 1 and external input clock 2 0 1 Cin/16 RC-oscillator 1 and RC-oscillator 2 3 1 0 Cin/16 RC-oscillator 1 and 4-MHz crystal oscillator 4 0 0 32 kHz RC-oscillator 1 and 32-kHz crystal oscillator Note: 5.6 Selected Oscillators If the bit CCS = 0 in the CM-register the RC-oscillator 1 always stops. Power-down Modes The sleep mode is a shut-down condition which is used to reduce the average system power consumption in applications where the microcontroller is not fully utilized. In this mode, the system clock is stopped. The sleep mode is entered via the SLEEP instruction. This instruction sets the interrupt enable bit (I) in the condition code register to enable all interrupts and stops the core. During the sleep mode the peripheral modules remain active and are able to generate interrupts. The microcontroller exits the sleep mode by carrying out any interrupt or a reset. The sleep mode can only be kept when none of the interrupt pending or active register bits are set. The application of the $AUTOSLEEP routine ensures the correct function of the sleep mode. For standard applications use the $AUTOSLEEP routine to enter the power-down mode. Using the SLEEP instruction instead of the $AUTOSLEEP following an I/O instruction requires the insertion of 3 non-I/O instruction cycles (for example NOP, NOP, NOP) between the IN or OUT command and the SLEEP command. The total power consumption is directly proportional to the active time of the microcontroller. For a rough estimation of the expected average system current consumption, the following formula should be used: t active I total ( V DD ,f syscl ) = I Sleep + ⎛ I DD × --------------⎞ IDD depends on VDD and fsyscl ⎝ t total ⎠ The ATAM894 has various power-down modes. During the sleep mode the clock for the MARC4 core is stopped. With the NSTOP bit in the clock management register (CM) it is programmable if the clock for the on-chip peripherals is active or stopped during the sleep mode. If the clock for the core and the peripherals is stopped the selected oscillator is switched off. An exception is the 32-kHz oscillator, if it is selected it runs continuously independent of the NSTOP bit. If the oscillator is stopped or the 32-kHz oscillator is selected, power consumption is extremely low. Power-down Modes Table 5-8. Mode CPU Core OscStop(1) Brown-out Function RC-Oscillator 1 RC-Oscillator 2 4-MHz Oscillator 32-kHz Oscillator External Input Clock Active RUN NO Active RUN RUN YES Power-down SLEEP NO Active RUN RUN YES SLEEP SLEEP YES STOP STOP RUN STOP Note: 1. Osc-Stop = SLEEP and NSTOP and WDL 21 4679D–4BMCU–05/05 6. Peripheral Modules 6.1 Addressing Peripherals Accessing the peripheral modules takes place via the I/O bus (see Figure 6-1). The IN or OUT instructions allow direct addressing of up to 16 I/O modules. A dual register addressing scheme has been adopted to enable direct addressing of the primary register. To address the auxiliary register, the access must be switched with an auxiliary switching module. Thus, a single IN (or OUT) to the module address will read (or write into) the module primary register. Accessing the auxiliary register is performed with the same instruction preceded by writing the module address into the auxiliary switching module. Byte wide registers are accessed by multiple IN- (or OUT-) instructions. For more complex peripheral modules, with a larger number of registers, extended addressing is used. In this case a bank of up to 16 subport registers are indirectly addressed with the subport address. The first OUT-instruction writes the subport address to the subaddress register, the second IN- or OUT-instruction reads data from or writes data to the addressed subport. Figure 6-1. Example of I/O Addressing Module M1 Module ASW (Address Pointer) Subaddress Reg. Module M2 Bank of Primary Regs. Auxiliary Switch Module Subport FH 1 Module M3 Aux. Reg. 5 Subport EH Subport 1 Primary Reg. Primary Reg. Primary Reg. Subport 0 2 3 6 4 I/O bus to other modules Indirect Subport Access Dual Register Access (Primary Register Write) (Subport Register Write) Addr. (SPort) Addr. (M1) OUT 1 2 SPort_Data Addr. (M1) Example of qFORTH Program Code Addr. (SPort) Addr. (M1) OUT 2 Prim._Data Addr. (M2) OUT 4 Addr. (M2) Addr. (ASW) OUT 5 Aux._Data Addr. (M2) OUT 6 (Auxiliary Register Write) Addr. (M1) IN Prim._Data Addr. (M3) OUT (Primary Register Read) 6 Addr. (M3) IN (Primary Register Read) 3 (Subport Register Write Byte) 1 Addr. (SPort) Addr. (M1) OUT 2 SPort_Data (lo) Addr. (M1) OUT 2 SPort_Data (hi) Addr. (M1) OUT Addr. (M2) IN (Auxiliary Register Read ) 4 5 (Subport Register Read Byte) 1 (Primary Register Write) 3 OUT (Subport Register Read) 1 Single Register Access Addr. (SPort) Addr. (M1) OUT Addr. (M2) Addr. (ASW) OUT Addr. (M2) IN (Auxiliary Register Write Byte) 4 Addr. (M2) Addr. (ASW) OUT 2 Addr. (M1) IN (hi) 5 Aux._Data (lo) Addr. (M2) OUT 2 Addr. (M1) IN (lo) 5 Aux._Data (hi) Addr. (M2) OUT Addr. (ASW) = Auxililiary Switch Module Address Addr. (Mx) = Module Mx Address Addr. (SPort) = Subport Address Prim._Data = Data to be written into Primary Register Aux._Data = Data to be written into Auxiliary Register Aux._Data (hi) = Data to be written into Auxiliary Register (high nibble) SPort_Data (lo) = Data to be written into Subport (low nibble) SPort_Data (hi) = Data to be written into Subport (high nibble) (lo) = SPort_Data (low nibble) (hi) = SPort_Data (high nibble) Aux._Data (lo) = Data to be written into Auxiliary Register (low nibble) 22 ATAM894 4679D–4BMCU–05/05 ATAM894 Table 6-1. Peripheral Addresses Port Address Name Write/Read Reset Value Register Function Module Type See Page 1 P1DAT W/R 1xx1b Port 1 - data register/input data M3 page 24 2 P2DAT W/R 1111b Port 2 - data register/pin data M2 page 26 P2CR W 1111b Port 2 - control register SC W 1x11b System configuration register M3 page 20 CWD R xxxxb Watchdog reset M3 page 13 CM W 1111b Clock management register M2 page 20 P4DAT W/R 1111b Port 4 - data register/pin data M2 page 29 P4CR W 1111 1111b Port 4 - control register (byte) P5DAT W/R 1111b Port 5 - data register/pin data P5CR W 1111 1111b Port 5 - control register (byte) P6DAT W/R 1xx1b Port 6 - data register/pin data P6CR W 1111b Port 6 - control register (byte) T12SUB W – Auxiliary 3 Auxiliary 4 Auxiliary 5 Auxiliary 6 Auxiliary 7 page 26 page 29 M2 page 28 page 28 M2 page 30 page 30 Data to Timer 1/2 subport M1 page 22 Subport address 0 T2C W 0000b Timer 2 control register M1 page 43 1 T2M1 W 1111b Timer 2 mode register 1 M1 page 43 2 T2M2 W 1111b Timer 2 mode register 2 M1 page 45 3 T2CM W 0000b Timer 2 compare mode register M1 page 45 4 T2CO1 W 1111b Timer 2 compare register 1 M1 page 46 5 T2CO2 W 1111 1111b Timer 2 compare register 2 (byte) M1 page 46 6 – – – Reserved 7 – – – Reserved 8 T1C1 W 1111b M1 page 33 Timer 1 control register 1 9 T1C2 W x111b Timer 1 control register 2 M1 page 34 A WDC W 1111b Watchdog control register M1 page 34 ASW page 22 M2 page 70 B-F Reserved 8 ASW W 1111b 9 STB W xxxx xxxxb Serial transmit buffer (byte) SRB R xxxx xxxxb Serial receive buffer (byte) page 71 SIC1 W 1111b Serial interface control register 1 page 68 SISC W/R 1x11b Serial interface status/control register SIC2 W 1111b Serial interface control register 2 W/R – Auxiliary A Auxiliary B T3SUB Auxiliary/switch register Data to/from Timer 3 subport M2 page 70 page 69 M1 page 22 Subport address 0 T3M W 1111b Timer 3 mode register M1 page 55 1 T3CS W 1111b Timer 3 clock select register M1 page 57 2 T3CM1 W 0000b Timer 3 compare mode register 1 M1 page 58 3 T3CM2 W 0000b Timer 3 compare mode register 2 M1 page 58 4 T3CO1 W 1111 1111b Timer 3 compare register 1 (byte) M1 page 59 4 T3CP R xxxx xxxxb Timer 3 capture register (byte) M1 page 59 5 T3CO2 W 1111 1111b Timer 3 compare register 2 (byte) M1 page 59 W 1111b Reserved – Reserved 6 7-F C D, E F T3C W 0000b Timer 3 control register M3 page 56 T3ST R x000b Timer 3 status register M3 page 56 --- – Reserved VMC W 1111b Voltage monitor control register M3 page 14 VMST R xx11b Voltage monitor status register M3 page 14 23 4679D–4BMCU–05/05 6.2 Bi-directional Ports With the exception of Port 1 and Port 6, all other ports (2, 4 and 5) are 4 bits wide. Port 1 and Port 6 have a data width of 2 bits (bit 0 and bit 3). All ports may be used for data input or output. All ports are equipped with Schmitt trigger inputs and a variety of mask options for open drain, open source, full complementary outputs, pull-up and pull-down transistors. All Port Data Registers (PxDAT) are I/O mapped to the primary address register of the respective port address and the Port Control Register (PxCR), to the corresponding auxiliary register. There are five different directional ports available: 6.2.1 Port 1 2-bit wide bi-directional ports with automatic full bus width direction switching Port 2 4-bit wide bit-wise-programmable I/O port Port 5 4-bit wide bit-wise-programmable bi-directional port with optional strong pull-ups and programmable interrupt logic Port 4 4-bit wide bit-wise-programmable bi-directional port also provides the I/O interface to Timer 2, SSI, voltage monitor input and external interrupt input Port 6 2-bit wide bit-wise-programmable bi-directional port also provides the I/O interface to Timer 3 and external interrupt input Bi-directional Port 1 In Port 1 the data direction register is not independently software programmable, the direction of the complete port being switched automatically when an I/O instruction occurs (see Figure 6-2 on page 25). The port is switched to output mode via an OUT instruction and to input via an IN instruction. The data written to a port will be stored into the output data latches and appears immediately at the port pin following the OUT instruction. After RESET all output latches are set to '1' and the port is switched to input mode. An IN instruction reads the condition of the associated pins. Note: 24 Care must be taken when switching the bi-directional port from output to input. The capacitive pin loading at this port in conjunction with the high resistance pull-ups may cause the CPU to read the contents of the output data register rather than the external input state. To avoid this, one of the following programming techniques should be used: Use two IN-instructions and DROP the first data nibble. The first IN switches the port from output to input and the DROP removes the first invalid nibble. The second IN reads the valid pin state. Use an OUT-instruction followed by an IN-instruction. Via the OUT-instruction, the capacitive load is charged or discharged depending on the optional pull-up/pull-down configuration. Write a ’1’ for pins with pull-up resistors and a '0' for pins with pull-down resistors. ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-2. Bi-directional Port 1 VDD I/O Bus (1) (Data out) D (1) Static pull-up Switched pull-up Q BP1y P1DATy R (1) VDD Reset (Direction) (1) OUT S Q (1) IN R NQ Flash options Switched pull-down Static pull-down Master reset 6.2.2 Bi-directional Port 2 As all other bi-directional ports, this port includes a bit-wise-programmable Control Register (P2CR), which enables the individual programming of each port bit as input or output. It also opens up the possibility of reading the pin condition when in output mode. This is a useful feature for self testing and for serial bus applications. However, Port 2 has an increased drive capability and an additional low resistance pull-up/down transistor mask option. Care should be taken connecting external components to BP20/NTE. During any reset phase, the BP20/NTE input is driven towards VDD by an additional internal strong pull-up transistor. This pin must not be pulled down (active or passive) to VSS during reset by any external circuitry representing a resistor of less than 150 kΩ. This prevents the circuit from unintended switching to test mode enable through the application circuitry at pin BP20/NTE. Resistors less than 150 kΩ might lead to an undefined state of the internal test logic, thus disabling the application firmware. To avoid any conflict with the optional internal pull-down transistors, BP20 handles the pull-down options in a different way than all other ports. BP20 is the only port that switches off the pulldown transistors during reset. 25 4679D–4BMCU–05/05 Figure 6-3. Bi-directional Port 2 VDD Switched pull-up I/O Bus (1) (Data out) (1) Static Pull-up (1) I/O Bus D Q P2DATy BP2y S VDD (1) Master reset I/O Bus (1) D S Q (1) Static Pull-down P2CRy (1) (Direction) 6.2.2.1 Flash options Switched pull-down Port 2 Data Register (P2DAT) Primary register address: '2'hex Bit 3 P2DAT Note: 6.2.2.2 * P2DAT3 Bit 2 Bit 1 Bit 0 P2DAT2 P2DAT1 P2DAT0 Reset value: 1111b * Bit 3 = MSB, Bit 0 = LSB Port 2 Control Register (P2CR) Auxiliary register address: '2'hex P2CR Note: Bit 2 Bit 1 Bit 0 P2CR3 P2CR2 P2CR1 P2CR0 Reset value: 1111b Value 1111b means all pins in input mode Table 6-2. 26 Bit 3 Port 2 Control Register Code 3210 Function xxx1 BP20 in input mode xxx0 BP20 in output mode xx1x BP21 in input mode xx0x BP21 in output mode x1xx BP22 in input mode x0xx BP22 in output mode 1xxx BP23 in input mode 0xxx BP23 in output mode ATAM894 4679D–4BMCU–05/05 ATAM894 6.2.3 Bi-directional Port 5 As all other bi-directional ports, this port includes a bit-wise-programmable Control Register (P5CR), which allows the individual programming of each port bit as input or output. It also opens up the possibility of reading the pin condition when in output mode. This is a useful feature for self-testing and for serial bus applications. The port pins can also be used as external interrupt inputs (see Figure 6-4 on page 27 and Figure 6-5 on page 27). The interrupts (INT1 and INT6) can be masked or independently configured to trigger on either edge. The interrupt configuration and port direction is controlled by the Port 5 Control Register (P5CR). An additional low resistance pull-up/-down transistor mask option provides an internal bus pull-up for serial bus applications. The Port 5 Data Register (P5DAT) is I/O mapped to the primary address register of address '5'h and the Port 5 Control Register (P5CR) to the corresponding auxiliary register. The P5CR is a byte-wide register and is configured by writing first the low nibble and then the high nibble (see section ”Addressing Peripherals” on page 22). Bi-directional Port 5 Figure 6-4. Switched pull-up I/O Bus VDD (1) (1) Static pull-up VDD (Data out) (1) I/O Bus Q D P5DATy BP5y (1) S VDD Master reset (1) Figure 6-5. (1) (1) IN enable Static pull-down Switched pull-down Flash options Port 5 External Interrupts INT1 INT6 Data in BP52 Data in BP5 Bidir. Port Bidir. Port IN_Enable IN_Enable I/O-bus I/O-bus Data in BP53 Data in BP5 Bidir. Port Bidir. Port IN_Enable IN_Enable Decoder Decoder Decoder Decoder P5CR: P53M2 P53M1 P52M2 P52M1 P51M2 P51M1 P50M2 P50M1 1376 27 4679D–4BMCU–05/05 6.2.3.1 Port 5 Data Register (P5DAT) Primary register address: '5'hex P5DAT 6.2.3.2 Bit 3 Bit 2 Bit 1 Bit 0 P5DAT3 P5DAT2 P5DAT1 P5DAT0 Reset value: 1111b Port 5 Control Register (P5CR) Byte Write Auxiliary register address: '5'hex P5CR First write cycle Second write cycle Bit 3 Bit 2 Bit 1 Bit 0 P51M2 P51M1 P50M2 P50M1 Bit 7 Bit 6 Bit 5 Bit 4 P53M2 P53M1 P52M2 P52M1 Reset value: 1111b Reset value: 1111b P5xM2, P5xM1 – Port 5x Interrupt Mode/Direction Code Table 6-3. Port 5 Control Register Auxiliary Address: '5'hex First Write Cycle Second Write Cycle Code 3210 Function Code 3210 xx11 BP50 in input mode – interrupt disabled xx11 BP52 in input mode – interrupt disabled xx01 BP50 in input mode – rising edge interrupt xx01 BP52 in input mode – rising edge interrupt xx10 BP50 in input mode – falling edge interrupt xx10 BP52 in input mode – falling edge interrupt xx00 BP50 in output mode – interrupt disabled xx00 BP52 in output mode – interrupt disabled Function 11xx BP51 in input mode – interrupt disabled 11xx BP53 in input mode – interrupt disabled 01xx BP51 in input mode – rising edge interrupt 01xx BP53 in input mode – rising edge interrupt 10xx BP51 in input mode – falling edge interrupt 10xx BP53 in input mode – falling edge interrupt 00xx BP51 in output mode – interrupt disabled 00xx BP53 in output mode – interrupt disabled 6.2.4 Bi-directional Port 4 The bi-directional Port 4 is a bit-wise configurable I/O port and provides the external pins for the Timer 2, SSI and the voltage monitor input (VMI). As a normal port, it performs in exactly the same way as bi-directional Port 2 (see Figure 6-3 on page 26). Two additional multiplexes allow data and port direction control to be passed over to other internal modules (Timer 2, VM or SSI). The I/O pins for the SC and SD lines have an additional mode to generate an SSI-interrupt. All four Port 4 pins can be individually switched by the P4CR register. Figure 6-6 on page 29 shows the internal interfaces to bi-directional Port 4. 28 ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-6. Bi-directional Port 4 and Port 6 VDD I/O Bus Intx (1) (1) PxMRy PIn Static pull-up VDD POut (1) I/O Bus Switched pull-up Q D BPxy PxDATy S VDD (1) Master reset (Direction) I/O Bus D S (1) (1) Q Static pull-down PxCRy (1) Flash options PDir 6.2.4.1 Switched pull-down Port 4 Data Register (P4DAT) Primary register address: '4'hex P4DAT 6.2.4.2 Bit 3 Bit 2 Bit 1 Bit 0 P4DAT3 P4DAT2 P4DAT1 P4DAT0 Reset value: 1111b Port 4 Control Register (P4CR) Byte Write Auxiliary register address: '4'hex P4CR First write cycle Second write cycle Bit 3 Bit 2 Bit 1 Bit 0 P41M2 P41M1 P40M2 P40M1 Bit 7 Bit 6 Bit 5 Bit 4 P43M2 P43M1 P42M2 P42M1 Reset value: 1111b Reset value: 1111b P4xM2, P4xM1 – Port 4x Interrupt Mode/Direction Code 29 4679D–4BMCU–05/05 Table 6-4. Port 4 Control Register Auxiliary Address: '4'hex First Write Cycle Code 3210 Second Write Cycle Function Code 3210 Function xx11 BP40 in input mode xx11 BP42 in input mode xx10 BP40 in output mode xx10 BP42 in output mode xx01 BP40 enable alternate function (SC for SSI) xx0x BP42 enable alternate function (T2O for Timer 2) xx00 BP40 enable alternate function (falling edge interrupt input for INT3) 11xx BP43 in input mode 11xx BP41 in input mode 10xx BP43 in output mode 10xx BP41 in output mode 01xx BP43 enable alternate function (SD for SSI) 01xx BP41 enable alternate function (VMI for voltage monitor input) 00xx BP43 enable alternate function (falling edge interrupt input for INT3) 00xx BP41 enable alternate function (T2I external clock input for Timer 2) 6.2.5 6.2.5.1 – – Bi-directional Port 6 The bi-directional Port 6 is a bit-wise configurable I/O port and provides the external pins for the Timer 3. As a normal port, it performs in exactly the same way as bi-directional Port 6 (see Figure 6-6 on page 29). Two additional multiplexes allow data and port direction control to be passed over to other internal modules (Timer 3). The I/O pin for the T3I line has an additional mode to generate a Timer 3-interrupt. All two Port 6 pins can be individually switched by the P6CR register. Figure 6-6 on page 29 shows the internal interfaces to bi-directional Port 6. Port 6 Data Register (P6DAT) Primary register address: '6'hex P6DAT 6.2.5.2 Bit 3 Bit 2 Bit 1 Bit 0 P6DAT3 - - P6DAT0 Bit 3 Bit 2 Bit 1 Bit 0 P63M2 P63M1 P60M2 P60M0 Reset value: 1xx1b Port 6 Control Register (P6CR) Auxiliary register address: '6'hex P6CR Reset value: 1111b P6xM2, P6xM1 – Port 6x Interrupt Mode/Direction Code Table 6-5. Port 6 Control Register Auxiliary Address: ’6’hex 30 Write Cycle Code 3210 Function Code 3210 Function xx11 BP60 in input mode 11xx BP63 in input mode xx10 BP60 in output mode 10xx BP63 in output mode xx0x BP60 enable alternate port function (T3O for Timer 3) 0xxx BP63 enable alternate port function (T3I for Timer 3) ATAM894 4679D–4BMCU–05/05 ATAM894 6.3 Universal Timer/Counter/ Communication Module (UTCM) The Universal Timer/counter/Communication Module (UTCM) consists of three timers (Timer 1,Timer 2, Timer 3) and a Synchronous Serial Interface (SSI). • Timer 1 is an interval timer that can be used to generate periodic interrupts and as prescaler for Timer 2, Timer 3, the serial interface and the watchdog function. • Timer 2 is an 8/12-bit timer with an external clock input (T2I) and an output (T2O). • Timer 3 is an 8-bit timer/counter with its own input (T3I) and output (T3O). • The SSI operates as a two-wire serial interface or as shift register for modulation and demodulation. The modulator and demodulator units work together with the timers and shift the data bits into or out of the shift register. There is a multitude of modes in which the timers and the serial interface can work together. Figure 6-7. UTCM Block Diagram SYSCL from clock module SUBCL Timer 1 NRST Watchdog MUX INT2 Interval/Prescaler Timer 3 T1OUT Capture 3 T3I 8-bit Counter 3 MUX Compare 3/1 Control Demodulator 3 Modulator 3 T3O INT5 Compare 3/2 Timer 2 TOG3 4-bit Counter 2/1 MUX Compare 2/1 Modulator 2 T2O I/O bus Control POUT T2I 8-bit Counter 2/2 MUX DCG INT4 Compare 2/2 TOG2 SSI SCL Receive buffer MUX 8-bit shift register SC Control SD Transmit buffer INT3 31 4679D–4BMCU–05/05 6.3.1 Timer 1 The Timer 1 is an interval timer which can be used to generate periodic interrupts and as prescaler for Timer 2, Timer 3, the serial interface and the watchdog function. The Timer 1 consists of a programmable 14-stage divider that is driven by either SUBCL or SYSCL. The timer output signal can be used as prescaler clock or as SUBCL and as source for the Timer 1 interrupt. Because of other system requirements the Timer 1 output T1OUT is synchronized with SYSCL. Therefore, in the power-down mode SLEEP (CPU core →sleep and OSC-Stop →yes) the output T1OUT is stopped (T1OUT = 0). Nevertheless, the Timer 1 can be active in SLEEP and generate Timer 1 interrupts. The interrupt is maskable via the T1IM bit and the SUBCL can be bypassed via the T1BP bit of the T1C2 register. The time interval for the timer output can be programmed via the Timer 1 control register T1C1. This timer starts running automatically after any power-on reset! If the watchdog function is not activated, the timer can be restarted by writing into the T1C1 register with T1RM = 1. Timer 1 can also be used as a watchdog timer to prevent a system from stalling. The watchdog timer is a 3-bit counter that is supplied by a separate output of Timer 1. It generates a system reset when the 3-bit counter overflows. To avoid this, the 3-bit counter must be reset before it overflows. The application software has to accomplish this by reading the CWD register. After power-on reset the watchdog must be activated by software in the $RESET initialization routine. There are two watchdog modes, in one mode the watchdog can be switched on and off by software, in the other mode the watchdog is active and locked. This mode can only be stopped by carrying out a system reset. The watchdog timer operation mode and the time interval for the watchdog reset can be programmed via the watchdog control register (WDC). Figure 6-8. Timer 1 Module SYSCL SUBCL WDCL MUX CL1 14-bit Prescaler 4-bit Watchdog NRST INT2 T1CS T1BP T1MUX 32 T1IM T1OUT ATAM894 4679D–4BMCU–05/05 ATAM894 Timer 1 and Watchdog Figure 6-9. T1C2 T1C1 T1RM T1C2 T1C1 T1C0 T1BP T1IM 3 Write of the T1C1 register T1IM=0 T1MUX Decoder INT2 MUX for interval timer T1IM=1 T1OUT RES Q1 Q2 Q3 Q4 Q5 CL1 CL Q6 Q8 Q11 Q14 SUBCL Q8 Q11 Q14 Watchdog Divider/8 MUX for watchdog timer Decoder 2 WDC WDL WDCL Divider RESET RES WDR WDT1 WDT0 Read of the CWD register Watchdog mode control 6.3.1.1 RESET (NRST) Timer 1 Control Register 1 (T1C1) Address: '7'hex — Subaddress: '8'hex T1C1 Note: Bit 3* Bit 2 Bit 1 Bit 0 T1RM T1C2 T1C1 T1C0 Reset value: 1111b * Bit 3 = MSB, Bit 0 = LSB T1RM Timer 1 Restart Mode T1RM = 0, write access without Timer 1 restart T1RM = 1, write access with Timer 1 restart Note: if WDL = 0, Timer 1 restart is impossible T1C2 Timer 1 Control bit 2 T1C1 Timer 1 Control bit 1 T1C0 Timer 1 Control bit 0 The three bits T1C[2:0] select the divider for timer 1. The resulting time interval depends on this divider and the timer 1 input clock source. The timer input can be supplied by the system clock, the 32-kHz oscillator or via the clock management. If the clock management generates the SUBCL, the selected input clock from the RC-oscillator, 4-MHz oscillator or an external clock is divided by 16. 33 4679D–4BMCU–05/05 Timer 1 Control Bits Table 6-6. 6.3.1.2 T1C2 T1C1 T1C0 Divider Time Interval with SUBCL Time Interval with SUBCL = 32 kHz Time Interval with SYSCL = 2/1 MHz 0 0 0 2 0 0 1 4 SUBCL/2 61 µs 1 µs/2 µs SUBCL/4 122 µs 2 µs/4 µs 0 1 0 8 SUBCL/8 244 µs 4 µs/8 µs 0 1 1 16 SUBCL/16 488 µs 8 µs/16 µs 1 0 0 32 SUBCL/32 0.977 ms 16 µs/32 µs 1 0 1 256 SUBCL/256 7.812 ms 128 µs/256 µs 1 1 0 2048 SUBCL/2048 62.5 ms 1024 µs/2048 µs 1 1 1 16384 SUBCL/16384 500 ms 8192 µs/16384 µs Timer 1 Control Register 2 (T1C2) Address: '7'hex — Subaddress: '9'hex Bit 3 T1C2 Note: 6.3.1.3 (1) – Bit 2 Bit 1 Bit 0 T1BP T1CS T1IM Reset value: x111b 1. Bit 3 = MSB, Bit 0 = LSB T1BP Timer 1 SUBCL ByPassed T1BP = 1, TIOUT = T1MUX T1BP = 0, T1OUT = SUBCL T1CS Timer 1 input Clock Select T1CS = 1, CL1 = SUBCL (see Figure 6-8 on page 32) T1CS = 0, CL1 = SYSCL (see Figure 6-8 on page 32) T1IM Timer 1 Interrupt Mask T1IM = 1, disables Timer 1 interrupt T1IM = 0, enables Timer 1 interrupt Watchdog Control Register (WDC) Address: '7'hex — Subaddress: 'A'hex Bit 3 WDC Note: 34 (1) WDL Bit 2 Bit 1 Bit 0 WDR WDT1 WDT0 Reset value: 1111b 1. Bit 3 = MSB, Bit 0 = LSB WDL WatchDog Lock mode WDL = 1, the watchdog can be enabled and disabled by using the WDR bit WDL = 0, the watchdog is enabled and locked. In this mode the WDR bit has no effect. After the WDL bit is cleared, the watchdog is active until a system reset or power-on reset occurs WDR WatchDog Run and stop mode WDR = 1, the watchdog is stopped/disabled WDR = 0, the watchdog is active/enabled WDT1 WatchDog Time 1 WDT0 WatchDog Time 0 ATAM894 4679D–4BMCU–05/05 ATAM894 Both these bits control the time interval for the watchdog reset. Table 6-7. 6.3.2 6.3.2.1 Watchdog Time Control Bits WDT1 WDT0 Divider Delay Time to Reset with tin = 1/32 kHz Delay Time to Reset with tin = 1/(2/1 MHz) 0 0 512 15.625 ms 0.256 ms/0.512 ms 0 1 2048 62.5 ms 1.024 ms/2.048 ms 1 0 16384 0.5 s 8.2 ms/16.4 ms 1 1 131072 4s 65.5 ms/131 ms Timer 2 Features 8/12-bit timer for • Interrupt, square-wave, pulse and duty cycle generation • Baud-rate generation for the internal shift register • Manchester and Bi-phase modulation together with the SSI • Carrier frequency generation and modulation together with the SSI Timer 2 can be used as interval timer for interrupt generation, as signal generator or as baud-rate generator and modulator for the serial interface. It consists of a 4-bit and an 8-bit up counter stage which both have compare registers. The 4-bit counter stages of Timer 2 are cascadable as an 12-bit timer or as an 8-bit timer with a 4-bit prescaler. The timer can also be configured as an 8-bit timer and separate a 4-bit prescaler. The Timer 2 input can be supplied via the system clock, the external input clock (T2I), the Timer 1 output clock or the shift clock of the serial interface. The external input clock T2I is not synchronized with SYSCL. Therefore, it is possible to use Timer 2 with a higher clock speed than SYSCL. Furthermore, with that input clock the Timer 2 operates in the power-down mode SLEEP (CPU core →sleep and OSC-Stop →yes) as well as in POWER-DOWN (CPU core → sleep and OSC-Stop → no). All other clock sources supply no clock signal in SLEEP if NSTOP = 0. The 4-bit counter stages of Timer 2 have an additional clock output (POUT). Its output has a modulator stage that allows the generation of pulses as well as the generation and modulation of carrier frequencies. The Timer 2 output can modulate with the shift register data output to generate Bi-phase- or Manchester code. If the serial interface is used to modulate a bit-stream, the 4-bit stage of Timer 2 has a special task. The shift register can only handle bit-stream lengths divisible by 8. For other lengths, the 4-bit counter stage can be used to stop the modulator after the right bit-count is shifted out. If the timer is used for carrier frequency modulation, the 4-bit stage works together with an additional 2-bit duty cycle generator like a 6-bit prescaler to generate carrier frequency and duty cycle. The 8-bit counter is used to enable and disable the modulator output for a programmable count of pulses. 35 4679D–4BMCU–05/05 For programming the time interval, the timer has a 4-bit and an 8-bit compare register. For programming the timer function, it has four mode and control registers. The comparator output of stage 2 is controlled by a special compare mode register (T2CM). This register contains mask bits for the actions (counter reset, output toggle, timer interrupt) which can be triggered by a compare match event or the counter overflow. This architecture enables the timer function for various modes. The Timer 2 has a 4-bit compare register (T2CO1) and an 8-bit compare register (T2CO2). Both these compare registers are cascadable as a 12-bit compare register, or 8-bit compare register and 4-bit compare register. For 12-bit compare data value: m = x +1 0 ≤x ≤4095 For 8-bit compare data value: n=y+1 0 ≤y ≤255 For 4-bit compare data value: l = z +1 0 ≤z ≤15 Figure 6-10. Timer 2 I/O-bus P4CR T2M1 T2M2 T2I DCGO SYSCL T1OUT TOG3 SCL CL2/1 CL2/2 4-bit Counter 2/1 RES OVF1 POUT T2O DCG 8-bit Counter 2/2 RES OUTPUT OVF2 TOG2 T2C Compare 2/1 Control M2 Compare 2/2 MOUT to Modulator 3 INT4 Bi-phase Manchester modulator CM1 T2CO1 T2CM T2CO2 Timer 2 modulator output-stage SSI POUT SO Control I/O-bus SSI 36 SSI ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.2.2 Timer 2 Modes Mode 1: 12-bit Compare Counter The 4-bit stage and the 8-bit stage work together as a 12-bit compare counter. A compare match signal of the 4-bit and the 8-bit stage generates the signal for the counter reset, toggle flip-flop or interrupt. The compare action is programmable via the compare mode register (T2CM). The 4-bit counter overflow (OVF1) supplies the clock output (POUT) with clocks. The duty cycle generator (DCG) has to be bypassed in this mode. Figure 6-11. 12-bit Compare Counter POUT (CL2/1 /16) CL2/1 4-bit counter DCG OVF2 8-bit counter RES TOG2 RES INT4 4-bit compare 8-bit compare CM2 CM1 4-bit register Timer 2 output mode and T2OTM-bit T2D1, 0 8-bit register T2RM T2OTM T2IM T2CTM Mode 2: 8-bit Compare Counter with 4-bit Programmable Prescaler The 4-bit stage is used as a programmable prescaler for the 8-bit counter stage. In this mode, a duty cycle stage is also available. This stage can be used as an additional 2-bit prescaler or for generating duty cycles of 25%, 33% and 50%. The 4-bit compare output (CM1) supplies the clock output (POUT) with clocks. Figure 6-12. 8-bit Compare Counter DCGO POUT CL2/1 4-bit counter DCG OVF2 8-bit counter RES TOG2 RES INT4 4-bit compare 8-bit compare CM2 CM1 4-bit register T2D1, 0 Timer 2 output mode and T2OTM-bit 8-bit register T2RM T2OTM T2IM T2CTM 37 4679D–4BMCU–05/05 Mode 3/4: 8-bit Compare Counter and 4-bit Programmable Prescaler In these modes the 4-bit and the 8-bit counter stages work independently as a 4-bit prescaler and an 8-bit timer with an 2-bit prescaler or as a duty cycle generator. Only in the mode 3 and mode 4, can the 8-bit counter be supplied via the external clock input (T2I) which is selected via the P4CR register. The 4-bit prescaler is started via activating of mode 3 and stopped and reset in mode 4. Changing mode 3 and 4 has no effect for the 8-bit timer stage. The 4-bit stage can be used as prescaler for Timer 3, the SSI or to generate the stop signal for modulator 2 and modulator 3. Figure 6-13. 4-/8-bit Compare Counter DCGO T2I CL2/2 SYSCL DCG 8-bit counter OVF2 TOG2 RES INT4 8-bit compare CM2 Timer 2 output mode and T2OTM-bit P4CR P41M2, 1 TOG3 T1OUT SYSCL SCL MUX CL2/1 T2D1, 0 8-bit register T2OTM T2IM T2CTM 4-bit counter RES 4-bit compare T2CS1, 0 38 T2RM CM1 POUT 4-bit register ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.2.3 Timer 2 Output Modes The signal at the timer output is generated via modulator 2. In the toggle mode, the compare match event toggles the output T2O. For high resolution duty cycle modulation 8 bits or 12 bits can be used to toggle the output. In the duty-cycle burst modulator modes the DCG output is connected to T2O and switched on and off either by the toggle flip-flop output or the serial data line of the SSI. Modulator 2 also has 2 modes to output the content of the serial interface as Biphase or Manchester code. The modulator output stage can be configured by the output control bits in the T2M2 register. The modulator is started with the start of the shift register (SIR = 0) and stopped either by carrying out a shift register stop (SIR = 1) or compare match event of stage 1 (CM1) of Timer 2. For this task, Timer 2 mode 3 must be used and the prescaler has to be supplied with the internal shift clock (SCL). Figure 6-14. Timer 2 Modulator Output Stage DCGO SO TOG2 T2O RE SSI CONTROL Bi-phase/ Manchester modulator FE Toggle S1 S3 M2 S2 RES/SET Modulator 3 OMSK M2 T2OS2, 1, 0 T2TOP T2M2 6.3.2.4 Timer 2 Output Signals Timer 2 Output Mode 1 Toggle Mode A: A Timer 2 compare match toggles the output flip-flop (M2) →T2O Figure 6-15. Interrupt Timer/Square Wave Generator — the Output Toggles with Each Edge Compare Match Event Input Counter 2 T2R 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 Counter 2 CMx INT4 T2O 39 4679D–4BMCU–05/05 Toggle Mode B: A Timer 2 compare match toggles the output flip-flop (M2) →T2O Figure 6-16. Pulse Generator — the Timer Output Toggles with the Timer Start if the T2TS bit is Set Input Counter 2 T2R 0 0 0 1 2 3 4 5 6 7 4095/ 255 0 1 2 3 4 5 6 Counter 2 CMx INT4 T2O Toggle by start T2O Toggle Mode C: A Timer 2 compare match toggles the output flip-flop (M2) →T2O Figure 6-17. Pulse Generator — the Timer Toggles with Timer Overflow and Compare Match Input Counter 2 T2R 0 0 0 1 2 3 4 5 6 7 4095/ 255 0 1 2 3 4 5 6 Counter 2 CMx OVF2 INT4 T2O 40 ATAM894 4679D–4BMCU–05/05 ATAM894 Timer 2 Output Mode 2 Duty Cycle Burst Generator 1: The DCG output signal (DCGO) is given to the output, and gated by the output flip-flop (M2) Figure 6-18. Carrier Frequency Burst Modulation with Timer 2 Toggle Flip-flop Output DCGO 1 2 0 1 2 0 1 2 3 4 5 0 1 2 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 Counter 2 TOG2 M2 T2O Counter = compare register (= 2) Timer 2 Output Mode 3 Duty Cycle Burst Generator 2: The DCG output signal (DCGO) is given to the output, and gated by the SSI internal data output (SO) Figure 6-19. Carrier Frequency Burst Modulation with the SSI Data Output DCGO 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 Counter 2 Counter = compare register (= 2) TOG2 SO Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 Bit 9 Bit 10 Bit 11 Bit 12 Bit 13 T2O Timer 2 Output Mode 4 Bi-phase Modulator: Timer 2 Modulates the SSI Internal Data Output (SO) to Bi-phase Code. Figure 6-20. Bi-phase Modulation TOG2 SC 8-bit SR data SO 0 0 1 1 0 1 0 Bit 7 T2O 0 1 Bit 0 0 1 1 0 1 0 1 Data: 00110101 41 4679D–4BMCU–05/05 Timer 2 Output Mode 5 Manchester Modulator: Timer 2 Modulates the SSI internal data output (SO) to Manchester code Figure 6-21. Manchester Modulation TOG2 SC 8-bit SR data 0 SO 0 1 1 0 1 0 1 Bit 0 Bit 7 0 T2O 0 1 1 0 1 0 1 Bit 7 Bit 0 Data: 00110101 Timer 2 Output Mode 7 PWM Mode: Pulse-width modulation output on Timer 2 output pin (T2O) In this mode the timer overflow defines the period and the compare register defines the duty-cycle. During one period only the first compare match occurrence is used to toggle the timer output flip-flop. Until the overflow all further compare match are ignored. This avoids the situation that changing the compare register causes the occurrence of several compare match during one period. The resolution at the pulse-width modulation Timer 2 mode 1 is 12-bit and all other Timer 2 modes are 8-bit. Figure 6-22. PWM Modulation Input clock Counter 2/2 T2R 0 0 50 255 0 100 255 0 150 255 0 50 255 0 100 Counter 2/2 CM2 OVF2 load the next compare value INT4 T2O T1 T2 T 42 T2CO2 = 150 load T3 T load T1 T T2 T T ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.2.5 Timer 2 Registers Timer 2 has 6 control registers to configure the timer mode, the time interval, the input clock and its output function. All registers are indirectly addressed using extended addressing as described in section ”Addressing Peripherals” on page 22. The alternate functions of the Ports BP41 or BP42 must be selected with the Port 4 control register P4CR, if one of the Timer 2 modes require an input at T2I/BP41 or an output at T2O/BP42. 6.3.2.6 Timer 2 Control Register (T2C) Address: '7'hex — Subaddress: '0'hex Bit 3 Bit 2 Bit 1 Bit 0 T2C T2CS1 T2CS0 T2TS T2R T2CS1 Timer 2 Clock Select bit 1 T2CS0 Timer 2 Clock Select bit 0 T2TS Timer 2 Toggle with Start T2TS = 0, the output flip-flop of Timer 2 is not toggled with the timer start T2TS = 1, the output flip-flop of Timer 2 is toggled when the timer is started with T2R T2R Timer 2 Run T2R = 0, Timer 2 stop and reset T2R = 1, Timer 2 run Timer 2 Clock Select Bits Table 6-8. 6.3.2.7 Reset value: 0000b T2CS1 T2CS0 0 0 System clock (SYSCL) 0 1 Output signal of Timer 1 (T1OUT) 1 0 Internal shift clock of SSI (SCL) 1 1 Reserved Input Clock (CL 2/1) of Counter Stage 2/1 Timer 2 Mode Register 1 (T2M1) Address: '7'hex — Subaddress: '1'hex Bit 3 Bit 2 Bit 1 Bit 0 T2M1 T2D1 T2D0 T2MS1 T2MS0 T2D1 Timer 2 Duty cycle bit 1 T2D0 Timer 2 Duty cycle bit 0 T2MS1 Timer 2 Mode Select bit 1 T2MS0 Timer 2 Mode Select bit 0 Reset value: 1111b 43 4679D–4BMCU–05/05 Timer 2 Duty Cycle Bits Table 6-9. T2D1 T2D0 1 1 Bypassed (DCGO0) /1 1 0 Duty cycle 1/1 (DCGO1) /2 0 1 Duty cycle 1/2 (DCGO2) /3 0 0 Duty cycle 1/3 (DCG03) /4 Table 6-10. T2MS1 T2MS0 1 1 2 1 4 Additional Divider Effect Timer 2 Mode Select Bits Mode 3 6.3.2.8 Function of Duty Cycle Generator (DCG) 0 0 Clock Output (POUT) Timer 2 Modes 1 4-bit counter overflow (OVF1) 12-bit compare counter, the DCG have to be bypassed in this mode 0 4-bit compare output (CM1) 8-bit compare counter with 4-bit programmable prescaler and duty cycle generator 4-bit compare output (CM1) 8-bit compare counter clocked by SYSCL or the external clock input T2I, 4-bit prescaler run, the counter 2/1 starts after writing mode 3 4-bit compare output (CM1) 8-bit compare counter clocked by SYSCL or the external clock input T2I, 4-bit prescaler stop and resets 1 0 Duty Cycle Generator The duty cycle generator generates duty cycles of 25%, 33% or 50%. The frequency at the duty cycle generator output depends on the duty cycle and the Timer 2 prescaler setting. The DCG-stage can also be used as an additional programmable prescaler for Timer 2. Figure 6-23. DCG Output Signals DCGIN DCGO0 DCGO1 DCGO2 DCGO3 44 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.2.9 Timer 2 Mode Register 2 (T2M2) Address: '7'hex — Subaddress: '2'hex Bit 3 Bit 2 Bit 1 Bit 0 T2M2 T2TOP T2OS2 T2OS1 T2OS0 T2TOP Timer 2 Toggle Output Preset This bit allows the programmer to preset the Timer 2 output T2O. T2TOP = 0, resets the toggle outputs with the write cycle (M2 = 0) T2TOP = 1, sets toggle outputs with the write cycle (M2 = 1) Note: If T2R = 1, no output preset is possible T2OS2 Timer 2 Output Select bit 2 T2OS1 Timer 2 Output Select bit 1 T2OS0 Timer 2 Output Select bit 0 Table 6-11. Output Mode Reset value: 1111b Timer 2 Output Select Bits T2OS2 T2OS1 T2OS0 Clock Output 1 1 1 1 Toggle mode: a Timer 2 compare match toggles the output flip-flop (M2) →T2O 2 1 1 0 Duty cycle burst generator 1: the DCG output signal (DCG0) is given to the output and gated by the output flip-flop (M2) 3 1 0 1 Duty cycle burst generator 2: the DCG output signal (DCGO) is given to the output and gated by the SSI internal data output (SO) 4 1 0 0 Bi-phase modulator: Timer 2 modulates the SSI internal data output (SO) to Bi-phase code 5 0 1 1 Manchester modulator: Timer 2 modulates the SSI internal data output (SO) to Manchester code 6 0 1 0 SSI output: T2O is used directly as SSI internal data output (SO) 7 0 0 1 PWM mode: an 8/12-bit PWM mode 8 0 0 0 Not allowed If one of these output modes is used the T2O alternate function of Port 4 must also be activated. 6.3.2.10 Timer 2 Compare and Compare Mode Registers Timer 2 has two separate compare registers, T2CO1 for the 4-bit stage and T2CO2 for the 8-bit stage of Timer 2. The timer compares the contents of the compare register current counter value and if it matches it generates an output signal. Depending on the timer mode, this signal is used to generate a timer interrupt, to toggle the output flip-flop as SSI clock or as a clock for the next counter stage. In the 12-bit timer mode, T2CO1 contains bits 0 to 3 and T2CO2 bits 4 to 11 of the 12-bit compare value. In all other modes, the two compare registers work independently as a 4- and 8-bit compare register. When assigned to the compare register a compare event will be suppressed. 45 4679D–4BMCU–05/05 6.3.2.11 Timer 2 Compare Mode Register (T2CM) Address: '7'hex — Subaddress: '3'hex T2CM Bit 2 Bit 1 Bit 0 T2OTM T2CTM T2RM T2IM Reset value: 0000b T2OTM Timer 2 Overflow Toggle Mask bit T2OTM = 0, disable overflow toggle T2OTM = 1, enable overflow toggle, a counter overflow (OVF2) toggles output flip-flop (TOG2). If the T2OTM bit is set, only a counter overflow can generate an interrupt except on the Timer 2 output mode 7 T2CTM Timer 2 Compare Toggle Mask bit T2CTM = 0, disable compare toggle T2CTM = 1, enable compare toggle, a match of the counter with the compare register toggles output flip-flop (TOG2). In Timer 2 output mode 7 and when the T2CTM bit is set, only a match of the counter with the compare register can generate an interrupt T2RM Timer 2 Reset Mask bit T2RM = 0, disable counter reset T2RM = 1, enable counter reset, a match of the counter with the compare register resets the counter T2IM Timer 2 Interrupt Mask bit T2IM = 0, disable Timer 2 interrupt T2IM = 1, enable Timer 2 interrupt Table 6-12. 6.3.2.12 Bit 3 Timer 2 Toggle Mask Bits Timer 2 Output Mode T2OTM T2CTM Timer 2 Interrupt Source 1, 2, 3, 4, 5 and 6 0 x Compare match (CM2) 1, 2, 3, 4, 5 and 6 1 x Overflow (OVF2) 7 x 1 Compare match (CM2) Timer 2 COmpare Register 1 (T2CO1) Address: '7'hex — Subaddress: '4'hex T2CO1 Write cycle Bit 3 Bit 2 Bit 1 Bit 0 Reset value: 1111b In prescaler mode the clock is bypassed if the compare register T2CO1 contains 0. 6.3.2.13 Timer 2 COmpare Register 2 (T2CO2) Byte Write Address: '7’hex — Subaddress: '5'hex T2CO2 46 First write cycle Bit 3 Bit 2 Bit 1 Bit 0 Reset value: 1111b Second write cycle Bit 7 Bit 6 Bit 5 Bit 4 Reset value: 1111b ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.3 Timer 3 6.3.3.1 Features • Two Compare Registers • Capture Register • Edge Sensitive Input with Zero Cross Detection Capability • Trigger and Single Action Modes • Output Control Modes • Automatic Modulation and Demodulation Modes • FSK Modulation • Pulse width Modulation (PWM) • Manchester Demodulation Together with SSI • Bi-phase Demodulation Together with SSI • Pulse-width Demodulation Together with SSI Figure 6-24. Timer 3 I/O-bus T3M T3CS T3I SCI T3EX T3I CM31 CP3 T3CP Demodulator 3 SI RES T3EX SYSCL T1OUT POUT CL3 INT5 8-bit Counter 3 T3C T3ST TOG3 SO Control M2 RES Compare 3/1 Compare 3/2 Control T3O Modulator 3 TOG2 T3CO1 T3CO2 T3CM1 T3CM2 I/O-bus Timer 2 SSI SSI Timer 3 consists of an 8-bit up-counter with two compare registers and one capture register. The timer can be used as event counter, timer and signal generator. Its output can be programmed as modulator and demodulator for the serial interface. The two compare registers enable various modes of signal generation, modulation and demodulation. The counter can be driven by internal and external clock sources. For external clock sources, it has a programmable edgesensitive input which can be used as counter input, capture signal input or trigger input. This timer input is synchronized with SYSCL. Therefore, in the power-down mode SLEEP (CPU core →sleep and OSC-Stop →yes), this timer input is stopped too. The counter is readable via its capture register while it is running. In capture mode, the counter value can be captured by a programmable capture event from the Timer 3 input or Timer 2 output. 47 4679D–4BMCU–05/05 A special feature of this timer is the trigger- and single-action mode. In trigger mode, the counter starts counting triggered by the external signal at its input. In single-action mode, the counter counts only one time up to the programmed compare match event. These modes are very useful for modulation, demodulation, signal generation, signal measurement and phase control. For phase control, the timer input is protected against negative voltages and has zero-cross detection capability. Timer 3 has a modulator output stage and input functions for demodulation. As modulator it works together with Timer 2 or the serial interface. When the shift register is used for modulation the data shifted out of the register is encoded bit-wise. In all demodulation modes, the decoded data bits are shifted automatically into the shift register. Figure 6-25. Counter 3 Stage TOG2 T3I T3EIM INT5 Control Capture register D NQ CL3 8-bit counter T3SM1 T3RM1 T3IM1 T3TM1 : T3M1 RES CM31 8-bit comparator Control TOG3 C31 C32 CM32 Compare register 1 NQ D T3SM2 T3RM2 T3IM2 T3TM2 : T3M2 Compare register 2 6.3.3.2 Timer/Counter Modes Timer 3 has 6 timer modes and 6 modulator/demodulator modes. The mode is set via the Timer 3 Mode Register T3M. In all these modes, the compare register and the compare-mode register belonging to it define the counter value for a compare match and the action of a compare match. A match of the current counter value with the content of one compare register triggers a counter reset, a Timer 3 interrupt or the toggling of the output flip-flop. The compare mode registers T3M1 and T3M2 contain the mask bits for enabling or disabling these actions. The counter can also be enabled to execute single actions with one or both compare registers. If this mode is set the corresponding compare match event is generated only once after the counter starts. 48 ATAM894 4679D–4BMCU–05/05 ATAM894 Most of the timer modes use their compare registers alternately. After the start has been activated, the first comparison is carried out via the compare register 1, the second is carried out via the compare register 2, the third is carried out again via the compare register 1 and so on. This makes it easy to generate signals with constant periods and variable duty cycle or to generate signals with variable pulse and space widths. If single-action mode is set for one compare register, the comparison is always carried out after the first cycle via the other compare register. The counter can be started and stopped via the control register T3C. This register also controls the initial level of the output before start. T3C contains the interrupt mask for a T3I input interrupt. Via the Timer 3 clock-select register, the internal or external clock source can be selected. This register selects also the active edge of the external input. An edge at the external input T3I can generate also an interrupt if the T3EIM bit is set and the Timer 3 is stopped (T3R = 0) in the T3C register. The status of the timer as well as the occurrence of a compare match or an edge detect of the input signal is indicated by the status register T2ST. This allows identification of the interrupt source because all these events share only one timer interrupt. Timer 3 compares data values. The Timer 3 has two 8-bit compare registers (T3CO1, T3CO2). The compare data value can be ‘m’ for each of the Timer 3 compare registers. 0 ≤x ≤255 The compare data value for the compare registers is: m = x +1 Timer 3 – Mode 1: Timer/Counter The selected clock from an internal or external source increments the 8-bit counter. In this mode, the timer can be used as event counter for external clocks at T3I or as timer for generating interrupts and pulses at T3O. The counter value can be read by the software via the capture register. Figure 6-26. Counter Reset with Each Compare Match T3R 0 0 0 1 2 3 0 1 2 3 4 5 0 1 2 3 0 1 2 3 Counter 3 CM31 CM32 INT5 T3O 49 4679D–4BMCU–05/05 Figure 6-27. Counter Reset with Compare Register 2 and Toggle with Start CL3 T3R 0 0 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 Counter 3 CM31 CM32 INT5 T3O Toggle by start T3O Figure 6-28. Single Action of Compare Register 1 T3R 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 Counter 3 CM31 CM32 T3O Toggle by start Timer 3 – Mode 2: Timer/Counter, External Trigger Restart and External Capture (with T3I Input) The counter is driven by an internal clock source. After starting with T3R, the first edge from the external input T3I starts the counter. The following edges at T3I load the current counter value into the capture register, resets the counter and restarts it. The edge can be selected by the programmable edge decoder of the timer input stage. If single-action mode is activated for one or both compare registers the trigger signal restarts the single action. Figure 6-29. Externally Triggered Counter Reset and Start Combined with Single-action Mode T3R 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 X X X 0 1 2 3 4 5 6 7 8 9 10 0 1 2 X X X X Counter 3 T3EX CM31 CM32 T3O 50 ATAM894 4679D–4BMCU–05/05 ATAM894 Timer 3 – Mode 3: Timer/Counter, Internal Trigger Restart and Internal Capture (with TOG2) The counter is driven by an internal or external (T3I) clock source. The output toggle signal of Timer 2 resets the counter. The counter value before the reset is saved in the capture register. If single-action mode is activated for one or both compare registers, the trigger signal restarts the single actions. This mode can be used for frequency measurements or as event counter with time gate (see section “Combination Mode 10”). Figure 6-30. Event Counter with Time Gate T3R T3I 0 0 1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 Counter 3 TOG2 T3CPRegister Capture value = 0 Capture value = 11 4 0 1 2 Capture value = 4 Timer 3 - Mode 4: Timer/Counter The timer runs as timer/counter in mode 1, but its output T3O is used as output for the Timer 2 output signal. Timer 3 – Mode 5: Timer/Counter, External Trigger Restart and External Capture (with T3I Input) The Timer 3 runs as timer/counter in mode 2, but its output T3O is used as output for the Timer 2 output signal. 6.3.3.3 Timer 3 Modulator/Demodulator Modes Timer 3 – Mode 6: Carrier Frequency Burst Modulation Controlled by Timer 2 Output Toggle Flip-Flop (M2) The Timer 3 counter is driven by an internal or external clock source. Its compare- and compare mode registers must be programmed to generate the carrier frequency via the output toggle flip-flop. The output toggle flip-flop of Timer 2 is used to enable or disable the Timer 3 output. Timer 2 can be driven by the toggle output signal of Timer 3 or any other clock source (see section “Combination Mode 11”). Timer 3 – Mode 7: Carrier Frequency Burst Modulation Controlled by SSI Internal Output (SO) The Timer 3 counter is driven by an internal or external clock source. Its compare- and compare mode registers must be programmed to generate the carrier frequency via the output toggle flip-flop. The output (SO) of the SSI is used to enable or disable the Timer 3 output. The SSI should be supplied with the toggle signal of Timer 2 (see section “Combination Mode 12”). 51 4679D–4BMCU–05/05 Timer 3 – Mode 8: FSK Modulation with Shift Register Data (SO) The two compare registers are used for generating two different time intervals. The SSI internal data output (SO) selects which compare register is used for the output frequency generation. A '0' level at the SSI data output enables the compare register 1. A '1' level enables compare register 2. The compare- and compare mode registers must be programmed to generate the two frequencies via the output toggle flip-flop. The SSI can be supplied with the toggle signal of Timer 2. The Timer 3 counter is driven by an internal or external clock source. The Timer 2 counter is driven by the Counter 3 (TOG3) (see section “Combination Mode 13”). Figure 6-31. FSK Modulation T3R 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 3 4 0 1 Counter 3 CM31 CM32 SO 0 1 0 T3O Timer 3 – Mode 9: Pulse-width Modulation with the Shift Register The two compare registers are used for generating two different time intervals. The SSI internal data output (SO) selects which compare register is used for the output pulse generation. In this mode both compare- and compare mode registers must be programmed for generating the two pulse widths. It is also useful to enable the single-action mode for extreme duty-cycles. Timer 2 is used as baud-rate generator and for the trigger restart of Timer 3. The SSI must be supplied with a toggle signal of Timer 2. The counter is driven by an internal or external clock source (see section “Combination Mode 7”). Figure 6-32. Pulse-width Modulation TOG2 SIR SO 0 1 0 1 SCO T3R Counter 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9101112131415 0 1 2 3 4 5 6 7 8 9 101112131415 0 1 2 3 4 CM31 CM32 T3O 52 ATAM894 4679D–4BMCU–05/05 ATAM894 Timer 3 – Mode 10: Manchester Demodulation/ Pulse-width Demodulation For Manchester demodulation, the edge detection stage must be programmed to detect each edge at the input. These edges are evaluated by the demodulator stage. The timer stage is used to generate the shift clock for the SSI. The compare register 1 match event defines the correct moment for shifting the state from the input T3I as the decoded bit into shift register - after that the demodulator waits for the next edge to synchronize the timer by a reset for the next bit. The compare register 2 can also be used to detect a time-out error and handle it with an interrupt routine (see section “Combination Mode 8”). Figure 6-33. Manchester Demodulation Timer 3 mode T3I Synchronize 1 Manchester demodulation mode 0 1 1 1 0 0 1 1 0 T3EX SI CM31 = SCI SR-DATA 1 1 1 0 0 1 1 BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 0 Timer 3 – Mode 11: Bi-phase Demodulation In the Bi-phase demodulation mode, the timer operates like in Manchester demodulation mode. The difference is that the bits are decoded via a toggle flip-flop. This flip-flop samples the edge in the middle of the bit-frame and the compare register 1 match event shifts the toggle flip-flop output into a shift register (see section “Combination Mode 9”). Figure 6-34. Bi-phase Demodulation Timer 3 mode T3I Synchronize 0 Bi-phase demodulation mode 0 1 1 0 1 0 0 1 T3EX Q1 = SI CM31 = SCI Reset Counter 3 SR-DATA 0 1 1 0 1 0 1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 0 Bit 0 53 4679D–4BMCU–05/05 Timer 3 – Mode 12: Timer/Counter with External Capture Mode (T3I) The counter is driven by an internal clock source and an edge at the external input T3I loads the counter value into the capture register. The edge can be selected with the programmable edge detector of the timer input stage. This mode can be used for signal and pulse measurements. Figure 6-35. External Capture Mode T3R T3I 0 0 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 1718 19 20 21 22 23 24 2526 27 28 29 30 3132 33 34 35 36 37 3839 40 41 Counter 3 T3CPRegister 6.3.3.4 Capture value = 35 Capture value = 17 Capture value = X Timer 3 Modulator for Carrier Frequency Burst Modulation If the output stage operates as pulse-width modulator for the shift register the output can be stopped with stage 1 of Timer 2. For this task, the timer mode 3 must be used and the prescaler must be supplied by the internal shift clock of the shift register. The modulator can be started with the start of the shift register (SIR = 0) and stopped either by a shift register stop (SIR = 1) or compare match event of stage 1 of Timer 2. For this task, the Timer 2 must be used in mode 3 and the prescaler stage must be supplied by the internal shift clock of the shift register. Figure 6-36. Modulator 3 0 T3 TOG3 Set M3 1 Res T3TOP 2 MUX Timer 3 Mode 6 7 9 other SO M2 3 SSI/ Control T3O T3O MUX 1 MUX 2 MUX 3 MUX 0 OMSK T3M 54 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.3.5 Timer 3 Demodulator for Bi-phase, Manchester and Pulse-width-modulated Signals The demodulator stage of Timer 3 can be used to decode Bi-phase, Manchester and puls-width-coded signals Figure 6-37. Timer 3 Demodulator 3 T3M SCI T3I Demodulator 3 T3EX SI Res CM31 Counter 3 Reset Counter 3 Control 6.3.3.6 Timer 3 Registers 6.3.3.7 Timer 3 Mode Register (T3M) Address: 'B'hex — Subaddress: '0'hex Bit 3 Bit 2 Bit 1 Bit 0 T3M3 T3M2 T3M1 T3M0 T3M3 Timer 3 Mode select bit 3 T3M2 Timer 3 Mode select bit 2 T3M1 Timer 3 Mode select bit 1 T3M0 Timer 3 Mode select bit 0 Reset value: 1111b Timer 3 Mode Select Bits Table 6-13. Mode T3M3 T3M2 T3M1 T3M0 Timer 3 Modes 1 1 1 1 1 Timer/counter with a read access 2 1 1 1 0 Timer/counter, external capture and external trigger restart mode (T3I) 3 1 1 0 1 Timer/counter, internal capture and internal trigger restart mode (TOG2) 4 1 1 0 0 Timer/counter mode 1 without output (T2O -> T3O) 5 1 0 1 1 Timer/counter mode 2 without output (T2O -> T3O) 6 1 0 1 0 Burst modulation with Timer 2 (M2) 7 1 0 0 1 Burst modulation with shift register (SO) 8 1 0 0 0 FSK modulation with shift register (SO) 9 0 1 1 1 Pulse-width modulation with shift register (SO) and Timer 2 (TOG2), internal trigger restart (SCO) -> counter reset 55 4679D–4BMCU–05/05 Timer 3 Mode Select Bits (Continued) Table 6-13. Mode T3M3 T3M2 T3M1 T3M0 10 0 1 1 0 Manchester demodulation/pulse-width demodulation(1) (T2O -> T3O) 11 0 1 0 1 Biphase demodulation (T2O -> T3O) 12 0 1 0 0 Timer/counter with external capture mode (T3I) 13 0 0 1 1 Not allowed 14 0 0 1 0 Not allowed 15 0 0 0 1 Not allowed 16 0 0 0 0 Not allowed Note: 6.3.3.8 Timer 3 Modes 1. In this mode, the SSI can be used only as demodulator (8-bit NRZ rising edge). All other SSI modes are not allowed. Timer 3 Control Register 1 (T3C) Write Primary register address: 'C'hex — Write Write Bit 2 Bit 1 Bit 0 T3EIM T3TOP T3TS T3R Reset value: 0000b T3EIM Timer 3 Edge Interrupt Mask T3EIM = 0, disables the interrupt when an edge event for Timer 3 occurs (T3I) T3EIM = 1, enables the interrupt when an edge event for Timer 3 occurs (T3I) T3TOP Timer 3 Toggle Output Preset T3TOP = 0, sets toggle output (M3) to '0' ............. ...... T3TOP = 1, sets toggle output (M3) to '1' ............. ...... Note: If T3R = 1, no output preset is possible T3TS Timer 3 Toggle with Start . T3TS = 0, Timer 3 output is not toggled during the start ...... ...... T3TS = 1, Timer 3 output is toggled if started with T3R T3R 6.3.3.9 Bit 3 Timer 3 Run ...... ...... T3R = 0, Timer 3 stop and reset ...... ...... T3R = 1, Timer 3 run Timer 3 Status Register 1 (T3ST) Read Primary register address: 'C'hex — Read Read Bit 2 Bit 1 Bit 0 --- T3ED T3C2 T3C1 Reset value: x000b T3ED Timer 3 Edge Detect This bit will be set by the edge-detect logic of Timer 3 input (T3I) T3C2 Timer 3 Compare 2 This bit will be set when a match occurs between Counter 3 and T3CO2 T3C1 Timer 3 Compare 1 This bit will be set when a match occurs between Counter 3 and T3CO1 Note: 56 Bit 3 The status bits T3C1, T3C2 and T3ED will be reset after a READ access to T3ST. ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.3.10 Timer 3 Clock Select Register (T3CS) Address: 'B'hex — Subaddress: '1'hex T3CS Bit 2 Bit 1 Bit 0 T3E1 T3E0 T3CS1 T3CS0 T3E1 Timer 3 Edge select bit 1 T3E0 Timer 3 Edge select bit 0 Table 6-14. Reset value: 1111b Timer 3 Edge Select Bits T3E1 T3E0 1 1 – 1 0 Positive edge at T3I pin 0 1 Negative edge at T3I pin 0 0 Each edge at T3I pin Timer 3 Input Edge Select (T3I) T3CS1 Timer 3 Clock Source select bit 1 T3CS0 Timer 3 Clock Source select bit 0 Table 6-15. 6.3.3.11 Bit 3 Timer 3 Clock Select Bits T3CS1 TCS0 1 1 Counter 3 Input Signal (CL3) System clock (SYSCL) 1 0 Output signal of Timer 2 (POUT) 0 1 Output signal of Timer 1 (T1OUT) 0 0 External input signal from T3I edge detect Timer 3 Compare- and Compare Mode Register Timer 3 has two separate compare registers T3CO1 and T3CO2 for the 8-bit stage of Timer 3. The timer compares the content of the compare register with the current counter value. If both match, it generates a signal. This signal can be used for the counter reset, to generate a timer interrupt, for toggling the output flip-flop, as SSI clock or as clock for the next counter stage. For each compare register, a compare-mode register exists. These registers contain mask bits to enable or disable the generation of an interrupt, a counter reset, or an output toggling with the occurrence of a compare match of the corresponding compare register. The mask bits for activating the single-action mode can also be located in the compare mode registers. When assigned to the compare register a compare event will be suppressed. 57 4679D–4BMCU–05/05 6.3.3.12 Timer 3 Compare Mode Register 1 (T3CM1) Address: 'B'hex — Subaddress: '2'hex T3CM1 Bit 3 Bit 2 Bit 1 Bit 0 T3SM1 T3TM1 T3RM1 T3IM1 Reset value: 0000b T3SM1 Timer 3 Single action Mask bit 1 T3SM1 = 0, disables single-action compare mode T3SM1 = 1, enables single-compare mode. After this bit is set, the compare register (T3CO1) is used until the next compare match T3TM1 Timer 3 compare Toggle action Mask bit 1 T3TM1 = 0, disables compare toggle T3TM1 = 1, enables compare toggle. A match of Counter 3 with the compare register (T3CO1) toggles the output flip-flop (TOG3) T3RM1 Timer 3 Reset Mask bit 1 T3RM1 = 0, disables counter reset T3RM1 = 1, enables counter reset. A match of Counter 3 with the compare register (T3CO1) resets the Counter 3 T3IM1 Timer 3 Interrupt Mask bit 1 T3RM1 = 0, disables Timer 3 interrupt for T3CO1 register. T3RM1 = 1, enables Timer 3 interrupt for T3CO1 register T3CM1 contains the mask bits for the match event of the Counter 3 compare register 1 6.3.3.13 Timer 3 Compare Mode Register 2 (T3CM2) Address: 'B'hex — Subaddress: '3'hex T3CM2 Bit 3 Bit 2 Bit 1 Bit 0 T3SM2 T3TM2 T3RM2 T3IM2 Reset value: 0000b T3SM2 Timer 3 Single action Mask bit 2 T3SM2 = 0, disables single-action compare mode T3SM2 = 1, enables single-compare mode. After this bit is set, the compare register (T3CO2) is used until the next compare match T3TM2 Timer 3 compare Toggle action Mask bit 2 T3TM2 = 0, disables compare toggle T3TM2 = 1, enables compare toggle. A match of Counter 3 with the compare register (T3CO2) toggles the output flip-flop (TOG3) T3RM2 Timer 3 Reset Mask bit 2 T3RM2 = 0, disables counter reset T3RM2 = 1, enables counter reset. A match of Counter 3 with the compare register (T3CO2) resets the Counter 3 T3IM2 Timer 3 Interrupt Mask bit 2 T3RM2 = 0, disables Timer 3 interrupt for T3CO2 register T3RM2 = 1, enables Timer 3 interrupt for T3CO2 register T3CM2 contains the mask bits for the match event of Counter 3 compare register 2 58 ATAM894 4679D–4BMCU–05/05 ATAM894 The compare registers and corresponding counter reset masks can be used to program the counter time intervals and the toggle masks can be used to program the output signal. The single-action mask can also be used in this mode. It starts operating after the timer started with T3R. 6.3.3.14 Timer 3 COmpare Register 1 (T3CO1) Byte Write Address: 'B'hex — Subaddress: '4'hex High Nibble Second write cycle Bit 7 Bit 6 Bit 5 Bit 4 Reset value: 1111b Bit 0 Reset value: 1111b Low Nibble First write cycle 6.3.3.15 Bit 3 Bit 2 Bit 1 Timer 3 COmpare Register 2 (T3CO2) Byte Write Address: 'B'hex — Subaddress: '5'hex High Nibble Second write cycle Bit 7 Bit 6 First write cycle Bit 3 Bit 2 Bit 5 Bit 4 Reset value: 1111b Bit 0 Reset value: 1111b Low Nibble Bit 1 6.3.3.16 Timer 3 Capture Register The counter content can be read via the capture register. There are two ways to use the capture register. In modes 1 and 4, it is possible to read the current counter value directly out of the capture register. In the capture modes 2, 3, 5 and 12, a capture event like an edge at the Timer 3 input or a signal from Timer 2 stores the current counter value into the capture register. This counter value can be read from the capture register. 6.3.3.17 Timer 3 CaPture Register (T3CP) Byte Read Address: 'B'hex — Subaddress: ’4'hex High Nibble First read cycle Bit 7 Bit 6 Bit 5 Bit 4 Reset value: xxxxb Bit 0 Reset value: xxxxb Low Nibble Second read cycle Bit 3 Bit 2 Bit 1 59 4679D–4BMCU–05/05 6.3.4 6.3.4.1 Synchronous Serial Interface (SSI) SSI Features • 2- and 3-wire NRZ • 2-wire mode (MCL compatible), additional internal 2-wire link for multi-chip packaging solutions • With Timer 2 – Bi-phase modulation – Manchester modulation – Pulse-width demodulation – Burst modulation • With Timer 3 – Pulse-width modulation (PWM) – FSK modulation – Bi-phase demodulation – Manchester demodulation – Pulse-width demodulation – Pulse position Demodulation 6.3.4.2 SSI Peripheral Configuration The synchronous serial interface (SSI) can be used either for serial communication with external devices such as EEPROMs, shift registers, display drivers, other microcontrollers, or as a means for generating and capturing on-chip serial streams of data. External data communication takes place via the Port 4 (BP4), a multi-functional port which can be software configured by writing the appropriate control word into the P4CR register. The SSI can be configured in any of the following ways: 1. 2-wire external interface for bi-directional data communication with one data terminal and one shift clock. The SSI uses the Port BP43 as a bi-directional serial data line (SD) and BP40 as shift clock line (SC). 2. 3-wire external interface for simultaneous input and output of serial data, with a serial input data terminal (SI), a serial output data terminal (SO) and a shift clock (SC). The SSI uses BP40 as shift clock (SC), while the serial data input (SI) is applied to BP43 (configured in P4CR as input!). Serial output data (SO) in this case is passed through to BP42 (configured in P4CR to T2O) via the Timer 2 output stage (T2M2 configured in mode 6). 3. Timer/SSI combined modes - the SSI used together with Timer 2 or Timer 3 is capable of performing a variety of data modulation and demodulation functions (see section “Timer”). The modulating data is converted by the SSI into a continuous serial stream of data which is in turn modulated in one of the timer functional blocks. Serial demodulated data can be serially captured in the SSI and read by the controller. In the Timer 3 modes 10 and 11 (demodulation modes) the SSI can only be used as demodulator. 4. Multi-chip link (MCL) – the SSI can also be used as an interchip data interface for use in single package multi-chip modules or hybrids. For such applications, the SSI is provided with two dedicated pads (MCL_SD and MCL_SC) which act as a two-wire chipto-chip link. The MCL can be activated by the MCL control bit. Should these MCL pads be used by the SSI, the standard SD and SC pins are not required and the corresponding Port 4 ports are available as conventional data ports. 60 ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-38. Block Diagram of the Synchronous Serial Interface I/O-bus Timer 2/Timer 3 SIC1 SIC2 SISC Control SC SO INT3 SI SCI SC SSI-Control MCL_SC TOG2 POUT T1OUT SYSCL Output SO /2 Shift_CL MSB 8-bit Shift Register STB SI LSB MCL_SD SD SRB Receive Buffer Transmit Buffer I/O-bus 6.3.4.3 General SSI Operation The SSI is comprised essentially of an 8-bit shift register with two associated 8-bit buffers the receive buffer (SRB) for capturing the incoming serial data and a transmit buffer (STB) for intermediate storage of data to be serially output. Both buffers are directly accessible by software. Transferring the parallel buffer data into and out of the shift register is controlled automatically by the SSI control, so that both single byte transfers or continuous bit streams can be supported. The SSI can generate the shift clock (SC) either from one of several on-chip clock sources or accept an external clock. The external shift clock is output on, or applied to the Port BP40. Selection of an external clock source is performed by the Serial Clock Direction control bit (SCD). In the combinational modes, the required clock is selected by the corresponding timer mode. The SSI can operate in three data transfer modes - synchronous 8-bit shift mode, MCL compatible 9-bit shift modes or 8-bit pseudo MCL protocol (without acknowledge-bit). External SSI clocking is not supported in these modes. The SSI should thus generate and has full control over the shift clock so that it can always be regarded as an MCL Bus Master device. All directional control of the external data port used by the SSI is handled automatically and is dependent on the transmission direction set by the Serial Data Direction (SDD) control bit. This control bit defines whether the SSI is currently operating in Transmit (TX) mode or Receive (RX) mode. Serial data is organized in 8-bit telegrams which are shifted with the most significant bit first. In the 9-bit MCL mode, an additional acknowledge bit is appended to the end of the telegram for handshaking purposes (see section ”MCL Bus Protocol” on page 65). At the beginning of every telegram, the SSI control loads the transmit buffer into the shift register and proceeds immediately to shift data serially out. At the same time, incoming data is shifted into the shift register input. This incoming data is automatically loaded into the receive buffer when the complete telegram has been received. Thus, data can be simultaneously received and transmitted if required. 61 4679D–4BMCU–05/05 Before data can be transferred, the SSI must first be activated. This is performed by means of the SSI reset control (SIR) bit. All further operation then depends on the data directional mode (TX/RX) and the present status of the SSI buffer registers shown by the Serial Interface Ready Status Flag (SRDY). This SRDY flag indicates the (empty/full) status of either the transmit buffer (in TX mode), or the receive buffer (in RX mode). The control logic ensures that data shifting is temporarily halted at any time, if the appropriate receive/transmit buffer is not ready (SRDY = 0). The SRDY status will then automatically be set back to ‘1’ and data shifting resumed as soon as the application software loads the new data into the transmit register (in TX mode) or frees the shift register by reading it into the receive buffer (in RX mode). Another activity status (ACT) bit indicates the present status of the serial communication. The ACT bit remains high for the duration of the serial telegram or if MCL stop or start conditions are currently being generated. Both the current SRDY and ACT status can be read in the SSI status register. To deactivate the SSI, the SIR bit must be set high. 6.3.4.4 8-bit Synchronous Mode Figure 6-39. 8-bit Synchronous Mode SC (rising edge) SC (falling edge) DATA 0 0 1 1 0 1 0 Bit 7 SD/TO2 0 Bit 7 1 Bit 0 0 1 1 0 1 0 1 Bit 0 Data: 00110101 In the 8-bit synchronous mode, the SSI can operate as either a 2- or 3-wire interface (see section ”SSI Peripheral Configuration” on page 60). The serial data (SD) is received or transmitted in NRZ format, synchronized to either the rising or falling edge of the shift clock (SC). The choice of clock edge is defined by the Serial Mode Control bits (SM0,SM1). It should be noted that the transmission edge refers to the SC clock edge with which the SD changes. To avoid clock skew problems, the incoming serial input data is shifted in with the opposite edge. When used together with one of the timer modulator or demodulator stages, the SSI must be set in the 8-bit synchronous mode 1. In RX mode, as soon as the SSI is activated (SIR = 0), 8 shift clocks are generated and the incoming serial data is shifted into the shift register. This first telegram is automatically transferred into the receive buffer and the SRDY set to 0 indicating that the receive buffer contains valid data. At the same time an interrupt (if enabled) is generated. The SSI then continues shifting in the following 8-bit telegram. If, during this time the first telegram has been read by the controller, the second telegram will also be transferred in the same way into the receive buffer and the SSI will continue clocking in the next telegram. Should, however, the first telegram not have been read (SRDY = 1), then the SSI will stop, temporarily holding the second telegram in the shift register until a certain point of time when the controller is able to service the receive buffer. In this way no data is lost or overwritten. 62 ATAM894 4679D–4BMCU–05/05 ATAM894 Deactivating the SSI (SIR = 1) in mid-telegram will immediately stop the shift clock and latch the present contents of the shift register into the receive buffer. This can be used for clocking in a data telegram of less than 8 bits in length. Care should be taken to read out the final complete 8-bit data telegram of a multiple word message before deactivating the SSI (SIR = 1) and terminating the reception. After termination, the shift register contents will overwrite the receive buffer. Figure 6-40. Example of an 8-bit Synchronous Transmit Operation SC msb lsb 7 6 5 4 3 2 1 SD msb 0 lsb msb lsb 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 tx data 1 tx data 2 0 tx data 3 SIR SRDY ACT Interrupt (IFN = 0) Interrupt (IFN = 1) Write STB (tx data 1) Write STB (tx data 2) Write STB (tx data 3) Figure 6-41. Example of an 8-bit Synchronous Receive Operation SC lsb msb SD msb lsb msb 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 rx data 1 lsb 7 6 5 4 3 2 1 0 7 6 5 4 rx data 2 rx data 3 SIR SRDY ACT Interrupt (IFN = 0) Interrupt (IFN = 1) Read SRB (rx data 1) Read SRB (rx data 2) Read SRB (rx data 3) 63 4679D–4BMCU–05/05 6.3.4.5 9-bit Shift Mode In the 9-bit shift mode, the SSI is able to handle the MCL protocol (described below). It always operates as an MCL master device, i.e., SC is always generated and output by the SSI. Both the MCL start and stop conditions are automatically generated whenever the SSI is activated or deactivated by the SIR bit. In accordance with the MCL protocol, the output data is always changed in the clock low phase and shifted in on the high phase. Before activating the SSI (SIR = 0) and commencing an MCL dialog, the appropriate data direction for the first word must be set using the SDD control bit. The state of this bit controls the direction of the data port (BP43 or MCL_SD). Once started, the 8 data bits are, depending on the selected direction, either clocked into or out of the shift register. During the 9th clock period, the port direction is automatically switched over so that the corresponding acknowledge bit can be shifted out or read in. In transmit mode, the acknowledge bit received from the slave device is captured in the SSI Status Register (TACK) where it can be read by the controller. In receive mode, the state of the acknowledge bit to be returned to the slave device is predetermined by the SSI Status Register (RACK). Changing the directional mode (TX/RX) should not be performed during the transfer of an MCL telegram. One should wait until the end of the telegram which can be detected using the SSI interrupt (IFN = 1) or by interrogating the ACT status. Once started, a 9-bit telegram will always run to completion and will not be prematurely terminated by the SIR bit. So, if the SIR bit is set to '1' in telegram, the SSI will complete the current transfer and terminate the dialog with an MCL stop condition. Figure 6-42. Example of MCL Transmit Dialog Start Stop SC lsb msb SD 7 6 5 4 3 2 1 0 A msb lsb 7 6 5 4 3 2 1 0 A tx data 1 tx data 2 SRDY ACT Interrupt (IFN = 0) Interrupt (IFN = 1) SIR SDD Write STB (tx data 1) 64 Write STB (tx data 2) ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-43. Example of MCL Receive Dialog Start Stop SC lsb msb SD 7 6 5 4 3 2 1 0 A tx data 1 msb lsb 7 6 5 4 3 2 1 0 A rx data 2 SRDY ACT Interrupt (IFN = 0) Interrupt (IFN = 1) SIR SDD Write STB (tx data 1) Read SRB (rx data 2) 6.3.4.6 8-bit Pseudo MCL Mode In this mode, the SSI exhibits all the typical MCL operational features except for the acknowledge-bit which is never expected or transmitted. 6.3.4.7 MCL Bus Protocol The MCL protocol constitutes a simple 2-wire bi-directional communication highway via which devices can communicate control and data information. Although the MCL protocol can support multi-master bus configurations, the SSI in MCL mode is intended for use purely as a master controller on a single master bus system. So all reference to multiple bus control and bus contention will be omitted at this point. All data is packaged into 8-bit telegrams plus a trailing handshaking or acknowledge-bit. Normally the communication channel is opened with a so-called start condition, which initializes all devices connected to the bus. This is then followed by a data telegram, transmitted by the master controller device. This telegram usually contains an 8-bit address code to activate a single slave device connected onto the MCL bus. Each slave receives this address and compares it with its own unique address. The addressed slave device, if ready to receive data, will respond by pulling the SD line low during the 9th clock pulse. This represents a so-called MCL acknowledge. The controller detecting this affirmative acknowledge then opens a connection to the required slave. Data can then be passed back and forth by the master controller, each 8-bit telegram being acknowledged by the respective recipient. The communication is finally closed by the master device and the slave device put back into standby by applying a stop condition onto the bus. 65 4679D–4BMCU–05/05 Figure 6-44. MCL Bus Protocol 1 (1) (2) (4) (4) (3) (1) SC SD Start condition Data Data Data valid change valid Stop condition Bus not busy (1) Both data and clock lines remain HIGH. Start data transfer (2) A HIGH to LOW transition of the SD line while the clock (SC) is HIGH defines a START condition. Stop data transfer (3) A LOW to HIGH transition of the SD line while the clock (SC) is HIGH defines a STOP condition. Data valid (4) The state of the data line represents valid data when, after START condition, the data line is stable for the duration of the HIGH period of the clock signal. Acknowledge All address and data words are serially transmitted to and from the device in eight-bit words. The receiving device returns a zero on the data line during the ninth clock cycle to acknowledge word receipt. Figure 6-45. MCL Bus Protocol 2 SC 1 SD 6.3.4.8 Start 1st Bit n 8 8th Bit 9 ACK Stop SSI Interrupt The SSI interrupt INT3 can be generated either by an SSI buffer register status (i.e., transmit buffer empty or receive buffer full), the end of SSI data telegram or on the falling edge of the SC/SD pins on Port 4 (see P4CR). SSI interrupt selection is performed by the Interrupt Function control bit (IFN). The SSI interrupt is usually used to synchronize the software control of the SSI and inform the controller of the present SSI status. The Port 4 interrupts can be used together with the SSI or, if the SSI itself is not required, as additional external interrupt sources. In either case this interrupt is capable of waking the controller out of sleep mode. To enable and select the SSI relevant interrupts use the SSI interrupt mask (SIM) and the Interrupt Function (IFN) while the Port 4 interrupts are enabled by setting appropriate control bits in P4CR register. 66 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.4.9 Modulation and Demodulation If the shift register is used together with Timer 2 or Timer 3 for modulation or demodulation purposes, the 8-bit synchronous mode must be used. In this case, the unused Port 4 pins can be used as conventional bi-directional ports. The modulation and demodulation stages, if enabled, operate as soon as the SSI is activated (SIR = 0) and cease when deactivated (SIR = 1). Due to the byte-orientated data control, the SSI (when running normally) generates serial bit streams which are submultiples of 8 bits. An SSI output masking (OMSK) function permits, however, the generation of bit streams of any length. The OMSK signal is derived indirectly from the 4-bit prescaler of the Timer 2 and masks out a programmable number of unrequired trailing data bits during the shifting out of the final data word in the bit stream. The number of non-masked data bits is defined by the value pre-programmed in the prescaler compare register. To use output masking, the modulator stop mode bit (MSM) must be set to '0' before programming the final data word into the SSI transmit buffer. This in turn, enables shift clocks to the prescaler when this final word is shifted out. On reaching the compare value, the prescaler triggers the OMSK signal and all following data bits are blanked. 6.3.4.10 Internal 2-wire Multi-chip Link Two additional on-chip pads (MCL_SC and MCL_SD) for the SC and the SD line can be used as chip-to-chip link for multi-chip applications. These pads can be activated by setting the MCL bit in the SISC register. They are also used as interface to the internal data EEPROM Figure 6-46. Multi-chip Link U505M SCL SDA Multi-chip link MCL_SC MCL_SD V DD V SS BP40/SC BP43/SD Microcontroller BP10 BP13 Figure 6-47. SSI Output Masking Function Timer 2 CL2/1 4-bit counter 2/1 SCL Compare 2/1 CM1 OMSK SO Control SC SSI-control Output TOG2 POUT T1OUT SYSCL SO /2 Shift_CL MSB 8-bit shift register SI LSB 67 4679D–4BMCU–05/05 6.3.4.11 Serial Interface Registers 6.3.4.12 Serial Interface Control Register 1 (SIC1) Auxiliary register address: '9'hex SIC1 Bit 2 Bit 1 Bit 0 SIR SCD SCS1 SCS0 Reset value: 1111b Serial Interface Reset SIR = 1, SSI inactive SIR = 0, SSI active SIR Serial Clock Direction SCD = 1, SC line used as output SCD = 0, SC line used as input Note: This bit has to be set to '1' during the MCL mode and the Timer 3 mode 10 or 11 SCD SCS1 Serial Clock source Select bit 1 SCS0 Note: Bit 3 Serial Clock source Select bit 0 With SCD = '0' the bits SCS1 and SCS0 are insignificant Table 6-16. Serial Clock Source Select Bits SCS1 SCS0 Internal Clock for SSI 1 1 SYSCL/2 1 0 T1OUT/2 0 1 POUT/2 0 0 TOG2/2 • In transmit mode (SDD = 1) shifting starts only if the transmit buffer has been loaded (SRDY = 1). • Setting SIR bit loads the contents of the shift register into the receive buffer (synchronous 8-bit mode only). • In MCL modes, writing a 0 to SIR generates a start condition and writing a 1 generates a stop condition. 68 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.4.13 Serial Interface Control Register 2 (SIC2) Auxiliary register address: 'A'hex SIC2 Bit 3 Bit 2 Bit 1 Bit 0 MSM SM1 SM0 SDD Reset value: 1111b MSM Modular Stop Mode MSM = 1, modulator stop mode disabled (output masking off) MSM = 0, modulator stop mode enabled (output masking on) — used in modulation modes for generating bit streams which are not sub multiples of 8 bit. SM1 Serial Mode control bit 1 SM0 Serial Mode control bit 0 Table 6-17. Serial Mode Control Bits Mode SM1 SM0 1 1 1 8-bit NRZ-data changes with the rising edge of SC 2 1 0 8-bit NRZ-data changes with the falling edge of SC 3 0 1 9-bit two-wire MCL mode 4 0 0 8-bit two-wire pseudo MCL mode (no acknowledge) SDD Note: SSI Mode Serial Data Direction SDD = 1, transmit mode - SD line used as output (transmit data). SRDY is set by a transmit buffer write access SDD = 0, receive mode - SD line used as input (receive data). SRDY is set by a receive buffer read access SDD controls port directional control and defines the reset function for the SRDY-flag 69 4679D–4BMCU–05/05 6.3.4.14 Serial Interface Status and Control Register (SISC) Primary register address: 'A'hex 6.3.4.15 Bit 3 Bit 2 Bit 1 Bit 0 SISC write MCL RACK SIM IFN Reset value: 1111b SISC read --- TACK ACT SRDY Reset value: xxxxb MCL Multi-Chip Link activation MCL = 1, multi-chip link disabled. This bit has to be set to '0' during transactions to/from the internal EEPROM MCL = 0, connects SC and SD, additionally to the internal multi-chip link pads RACK Receive ACKnowledge status/control bit for MCL mode RACK = 0, transmit acknowledge in next receive telegram RACK = 1, transmit no acknowledge in last receive telegram TACK Transmit ACKnowledge status/control bit for MCL mode TACK = 0, acknowledge received in last transmit telegram TACK = 1, no acknowledge received in last transmit telegram SIM Serial Interrupt Mask SIM = 1, disable interrupts SIM = 0, enable serial interrupt. An interrupt is generated IFN Interrupt FuNction IFN = 1, the serial interrupt is generated at the end of telegram IFN = 0, the serial interrupt is generated when the SRDY goes low (i.e., buffer becomes empty/full in transmit/receive mode) SRDY Serial interface buffer ReaDY status flag SRDY = 1, in receive mode: receive buffer empty in transmit mode: transmit buffer full SRDY = 0, in receive mode: receive buffer full in transmit mode: transmit buffer empty ACT Transmission ACTive status flag ACT = 1, transmission is active, i.e., serial data transfer. Stop or start conditions are currently in progress. ACT = 0, transmission is inactive Serial Transmit Buffer (STB) – Byte Write Primary register address: '9'hex First write cycle Bit 3 Bit 2 Bit 1 Bit 0 Reset value: xxxxb Second write cycle Bit 7 Bit 6 Bit 5 Bit 4 Reset value: xxxxb The STB is the transmit buffer of the SSI. The SSI transfers the transmit buffer into the shift register and starts shifting with the most significant bit. 70 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.4.16 Serial Receive Buffer (SRB) – Byte Read Primary register address: '9'hex First read cycle Bit 7 Bit 6 Bit 5 Bit 4 Reset value: xxxxb Second read cycle Bit 3 Bit 2 Bit 1 Bit 0 Reset value: xxxxb The SRB is the receive buffer of the SSI. The shift register clocks serial data in (most significant bit first) and the loads content into the receive buffer when the complete telegram has been received. 6.3.5 Combination Modes The UTCM consists of two timers (Timer 2 and Timer 3) and a serial interface. There is a multitude of modes in which the timers and serial interface can work together. The 8-bit wide serial interface operates as shift register for modulation and demodulation. The modulator and demodulator units work together with the timers and shift the data bits into or out of the shift register. 6.3.5.1 Combination Mode Timer 2 and SSI Figure 6-48. Combination Timer 2 and SSI I/O-bus P4CR T2M1 T2M2 T2I DCGO SYSCL T1OUT TOG3 SCL CL2/1 RES T2C OVF1 T2O CL2/2 4-bit Counter 2/1 DCG POUT Compare 2/1 8-bit Counter 2/2 RES Timer 2 - control OUTPUT OVF2 TOG2 Compare 2/2 MOUT INT4 POUT T2CO1 Bi-phase Manchester modulator CM1 T2CM T2CO2 TOG2 SO Timer 2 modulator output-stage Control I/O-bus SIC1 SIC2 SISC Control TOG2 POUT T1OUT SYSCL INT3 SCLI SO SC SSI-control MCL_SC SCL Output SO SI Shift_CL MSB 8-bit shift register STB MCL_SD SD LSB SRB Transmit buffer Receive buffer I/O-bus 71 4679D–4BMCU–05/05 Combination Mode 1: Burst Modulation SSI mode 1: 8-bit NRZ and internal data SO output to the Timer 2 modulator stage Timer 2 mode 1, 2, 3 or 4: 8-bit compare counter with 4-bit programmable prescaler and DCG Duty cycle burst generator Timer 2 output mode 3: Figure 6-49. Carrier Frequency Burst Modulation with the SSI Internal Data Output DCGO 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 Counter 2 Counter = compare register (= 2) TOG2 SO Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 Bit 9 Bit 10 Bit 11 Bit 12 Bit 13 T2O Combination Mode 2: Bi-phase Modulation 1 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 2 modulator stage Timer 2 mode 1, 2, 3 or 4: Timer 2 output mode 4: 8-bit compare counter with 4-bit programmable prescaler The modulator 2 of Timer 2 modulates the SSI internal data output to Bi-phase code Figure 6-50. Bi-phase Modulation 1 TOG2 SC 8-bit SR data SO 0 0 1 1 0 1 0 Bit 7 T2O 0 1 Bit 0 0 1 1 0 1 0 1 Data: 00110101 Combination Mode 3: Manchester Modulation 1 72 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 2 modulator stage Timer 2 mode 1, 2, 3 or 4: Timer 2 output mode 5: 8-bit compare counter with 4-bit programmable prescaler The modulator 2 of Timer 2 modulates the SSI internal data output to Manchester code ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-51. Manchester Modulation 1 TOG2 SC 8-bit SR data 0 SO 0 1 1 0 1 0 1 Bit 7 Bit 0 0 T2O 0 1 1 0 1 0 1 Bit 7 Bit 0 Data: 00110101 Combination Mode 4: Manchester Modulation 2 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 2 modulator stage Timer 2 mode 3: Timer 2 output mode 5: 8-bit compare counter and 4-bit prescaler The modulator 2 of Timer 2 modulates the SSI data output to Manchester code The 4-bit stage can be used as prescaler for the SSI to generate the stop signal for modulator 2. The SSI has a special mode to supply the prescaler with the shift clock. The control output signal (OMSK) of the SSI is used as stop signal for the modulator. This is an example for a 12-bit Manchester telegram: Figure 6-52. Manchester Modulation 2 SCLI Buffer full SIR Bit 7 Bit 6 SO Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SC MSM Timer 2 Mode 3 SCL Counter 2/1 0 0 0 0 0 Counter 2/1 = Compare Register 2/1 (= 4) 0 0 0 0 1 2 3 4 0 1 2 3 OMSK T2O 73 4679D–4BMCU–05/05 Combination Mode 5: Bi-phase Modulation 2 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 2 modulator stage Timer 2 mode 3: Timer 2 output mode 4: 8-bit compare counter and 4-bit prescaler The modulator 2 of Timer 2 modulates the SSI data output to Bi-phase code The 4-bit stage can be used as prescaler for the SSI to generate the stop signal for modulator 2. The SSI has a special mode to supply the prescaler via the shift clock. The control output signal (OMSK) of the SSI is used as a stop signal for the modulator. This is an example for a 13-bit Biphase telegram. Figure 6-53. Bi-phase Modulation SCLI Buffer full SIR Bit 7 Bit 6 SO Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 SC MSM Timer 2 Mode 3 SCL Counter 2/1 0 0 0 0 0 Counter 2/1 = Compare Register 2/1 (= 5) 0 0 0 0 1 2 3 4 5 0 1 2 OMSK T2O 74 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.5.2 Combination Mode Timer 3 and SSI Figure 6-54. Combination Timer 3 and SSI I/O-bus T3CS T3M T3I T3EX SC T3I T3EX SYSCL T1OUT POUT CL3 CM31 CP3 T3CP SI RES 8-bit Counter 3 T3C INT5 T3ST TOG3 SO Control RES Compare 3/1 Demodulator 3 Compare 3/2 Timer 3 - control T3O Modulator 3 M2 T3CO1 T3CO2 T3CM1 T3CM2 SI SC SIC1 TOG2 POUT T1OUT SYSCL SIC2 SISC Control INT3 SCLI SC SSI-control MCL_SC Output SO Shift_CL MSB 8-bit shift register STB Transmit buffer SI MCL_SD SI LSB SRB I/O-bus Receive buffer Combination Mode 6: FSK Modulation SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 3 Timer 3 mode 8: FSK modulation with shift register data (SO) The two compare registers are used to generate two varied time intervals. The SSI data output selects which compare register is used for the output frequency generation. A '0'-level at the SSI data output enables the compare register 1 and a '1'-level enables the compare register 2. The compare and compare mode registers must be programmed to generate the two frequencies via the output toggle flip-lop. The SSI can be supplied with the toggle signal of Timer 2 or any other clock source. The Timer 3 counter is driven by an internal or external clock source. 75 4679D–4BMCU–05/05 Figure 6-55. FSK Modulation T3R Counter 3 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 3 4 0 1 CM31 CM32 SO 0 1 0 T3O Combination Mode 7: Pulse-width Modulation (PWM) SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 3 Timer 3 mode 9: Pulse-width modulation with the shift register data (SO) The two compare registers are used to generate two varied time intervals. The SSI data output selects which compare register is used for the output pulse generation. In this mode, both compare and compare mode registers must be programmed to generate the two pulse width. It is also useful to enable the single-action mode for extreme duty cycles. Timer 2 is used as baudrate generator and for the triggered restart of Timer 3. The SSI must be supplied with the toggle signal of Timer 2. The counter is driven by an internal or external clock source. Figure 6-56. Pulse-width Modulation TOG2 SIR SO 0 1 0 1 SCO T3R Counter 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9101112131415 0 1 2 3 4 5 6 7 8 9 101112131415 0 1 2 3 4 CM31 CM32 T3O 76 ATAM894 4679D–4BMCU–05/05 ATAM894 Combination Mode 8: Manchester Demodulation/Pulse-width Demodulation SSI mode 1: 8-bit shift register internal data input (SI) and the internal shift clock (SCI) from the Timer 3 Timer 3 mode 10: Manchester demodulation/pulse-width demodulation with Timer 3 For Manchester demodulation, the edge detection stage must be programmed to detect each edge at the input. These edges are evaluated by the demodulator stage. The timer stage is used to generate the shift clock for the SSI. A compare register 1 match event defines the correct moment for shifting the state from the input T3I as the decoded bit into the shift register. After that, the demodulator waits for the next edge to synchronize the timer by a reset for the next bit. The compare register 2 can be used to detect a time error and handle it with an interrupt routine. Before activating the demodulator mode the timer and the demodulator stage must be synchronized with the bit-stream. The Manchester code timing consists of parts with the half bit-length and the complete bit-length. A synchronization routine must start the demodulator after an interval with the complete bit-length. The counter can be driven by any internal clock source. The output T3O can be used by Timer 2 in this mode. The Manchester decoder can also be used for pulse-width demodulation. The input must programmed to detect the positive edge. The demodulator and timer must be synchronized with the leading edge of the pulse. After that a counter match with the compare register 1 shifts the state at the input T3I into the shift register. The next positive edge at the input restarts the timer. Figure 6-57. Manchester Demodulation Timer 3 mode T3I Synchronize 1 Manchester demodulation mode 0 1 1 1 0 0 1 1 0 T3EX SI CM31 = SCI SR-DATA 1 1 1 0 0 1 1 BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 0 77 4679D–4BMCU–05/05 Combination Mode 9: Bi-phase Demodulation SSI mode 1: 8-bit shift register internal data input (SI) and the internal shift clock (SCI) from the Timer 3 Timer 3 mode 11: Bi-phase demodulation with Timer 3 In the Bi-phase demodulation mode the timer works like in the Manchester demodulation mode. The difference is that the bits are decoded with the toggle flip-flop. This flip-flop samples the edge in the middle of the bit-frame and the compare register 1 match event shifts the toggle flipflop output into shift register. Before activating the demodulation the timer and the demodulation stage must be synchronized with the bit-stream. The Bi-phase code timing consists of parts with the half bit-length and the complete bit-length. The synchronization routine must start the demodulator after an interval with the complete bit-length. The counter can be driven by any internal clock source and the output T3O can be used by Timer 2 in this mode. Figure 6-58. Bi-phase Demodulation Timer 3 mode T3I Synchronize 0 Bi-phase demodulation mode 0 1 1 0 1 1 0 1 0 1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 0 1 0 1 0 T3EX Q1 = SI CM31 = SCI Reset Counter 3 SR-DATA 78 0 Bit 0 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.5.3 Combination Mode Timer 2 and Timer 3 Figure 6-59. Combination Timer 3 and Timer 2 I/O-bus T3CS T3M T3I T3EX SCI T3I T3EX SYSCL T1OUT POUT CL3 CM31 CP3 T3CP SI Demodulator 3 RES 8-bit Counter 3 T3C INT5 T3ST TOG3 SO Control RES Compare 3/1 Compare 3/2 T3CO1 T3CO2 Timer 3 - control TOG2 T3CM1 T3O Modulator 3 M2 T3CM2 I/O-bus P4CR T2I SSI T2M1 T2M2 DCGO T2O TOG3 SYSCL T1OUT SCL CL2/1 CL2/2 4-bit Counter 2/1 RES OVF1 DCG POUT OUTPUT 8-bit Counter 2/2 RES OVF2 MOUT TOG2 T2C Compare 2/1 Timer 2 - control M2 Compare 2/2 Bi-phase Manchester modulator INT4 CM1 POUT T2CO1 I/O-bus T2CM T2CO2 SO Timer 2 modulator 2 output-stage SSI SSI Control (RE, FE, SCO, OMSK) Combination Mode 10: Frequency Measurement or Event Counter with Time Gate Timer 2 mode 1/2: Timer 2 output mode 1/6: Timer 3 mode 3: 12-bit compare counter/8-bit compare counter and 4-bit prescaler Timer 2 compare match toggles (TOG2) to the Timer 3 Timer/Counter; integrated trigger restart and integrated capture (with Timer 2 TOG2-signal) The counter is driven by an external (T3I) clock source. The output signal (TOG2) of Timer 2 resets the counter. The counter value before reset is saved in the capture register. If singleaction mode is activated for one or both compare registers, the trigger signal restarts also the single actions. This mode can be used for frequency measurements or as event counter with time gate. 79 4679D–4BMCU–05/05 Figure 6-60. Frequency Measurement T3R T3I 0 0 1 2 3 4 5 6 7 8 9 10 11121314151617 0 1 2 3 4 5 6 7 8 9 101112131415161718 0 1 2 3 4 5 Counter 3 TOG2 T3CPRegister Capture value = 0 Capture value = 17 Capt. value = 18 Figure 6-61. Event Counter with Time Gate T3R T3I 0 0 1 2 3 4 5 6 7 8 910 11 2 0 1 3 0 1 2 4 Counter 3 TOG2 T3CPRegister Capture value = 0 Capture value = 11 Cap. value = 4 Combination Mode 11: Burst Modulation 1 Timer 2 mode 1/2: Timer 2 output mode 1/6: Timer 3 mode 6: 12-bit compare counter/8-bit compare counter and 4-bit prescaler Timer 2 compare match toggles the output flip-flop (M2) to the Timer 3 Carrier frequency burst modulation controlled by Timer 2 output (M2) The Timer 3 counter is driven by an internal or external clock source. Its compare- and compare mode registers must be programmed to generate the carrier frequency with the output toggle flip-flop. The output toggle flip-flop (M2) of Timer 2 is used to enable and disable the Timer 3 output. The Timer 2 can be driven by the toggle output signal of Timer 3 (TOG3) or any other clock source. Figure 6-62. Burst Modulation 1 CL3 Counter 3 0 1 01 2 34 5 01 0 12 3 4 5 0 10 1 23 4 50 1 01 5 0 1 01 50 1 01 501 01 5 01 01 501 01 5 01 01 5 01 01 5 01 01 5 01 01 CM1 CM2 TOG3 M3 Counter 2/2 3 0 1 2 3 3 0 1 2 3 TOG2 M2 T3O 80 ATAM894 4679D–4BMCU–05/05 ATAM894 6.3.5.4 Combination Timer 2, Timer 3 and SSI Figure 6-63. Combination Timer 2, Timer 3 and SSI I/O-bus T3CS T3M T3I T3EX SCI Demodulator 3 T3I CP3 T3CP SI CM31 RES T3EX SYSCL T1OUT POUT CL3 8-bit Counter 3 T3C INT5 T3ST TOG3 SO Control RES Compare 3/1 Compare 3/2 Timer 3 - control TOG2 T3CO1 T3CO2 T3CM1 T3O Modulator 3 M2 T3CM2 SSI I/O-bus P4CR T2M1 T2M2 T2I DCGO T2O TOG3 SYSCL T1OUT CL2/1 RES SCL T2C CL2/2 4-bit Counter 2/1 OVF1 DCG POUT Compare 2/1 OUTPUT 8-bit Counter 2/2 RES Timer 2 - control OVF2 TOG2 MOUT M2 Compare 2/2 Bi-phase Manchester modulator INT4 CM1 POUT T2CO1 T2CM T2CO2 SO Control I/O-bus Control SIC1 SIC2 (RE, FE, SCO, OMSK) SISC TOG2 POUT T1OUT SYSCL Timer 2 modulator 2 output-stage INT3 SCLI SC SSI-control MCL_SC Output SO SI SCL Shift_CL MSB 8-bit shift register STB Transmit buffer LSB MCL_SD SI SRB I/O-bus Receive buffer 81 4679D–4BMCU–05/05 Combination Mode 12: Burst Modulation 2 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 3 Timer 2 output mode 2: Timer 2 output mode 1/6: 8-bit compare counter and 4-bit prescaler Timer 2 compare match toggles (TOG2) to the SSI Timer 3 mode 7: Carrier frequency burst modulation controlled by the internal output (SO) of SSI The Timer 3 counter is driven by an internal or external clock source. Its compare- and compare mode registers must be programmed to generate the carrier frequency with the output toggle flip-flop (M3). The internal data output (SO) of the SSI is used to enable and disable the Timer 3 output. The SSI can be supplied with the toggle signal of Timer 2. Figure 6-64. Burst Modulation 2 CL3 Counter 3 0 1 01 2 34 5 01 0 12 3 45 0 10 1 23 4 50 1 01 5 0 1 01 50 1 01 5 01 01 5 0 1 01 5 01 01 5 01 01 5 01 01 501 01 5 01 01 CM31 CM32 TOG3 M3 Counter 2/2 3 0 1 2 3 3 0 1 2 3 TOG2 SO T3O Combination Mode 13: FSK Modulation SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 3 Timer 2 output mode 3: Timer 2 output mode 1/6: 8-bit compare counter and 4-bit prescaler Timer 2 4-bit compare match signal (POUT) to the SSI Timer 3 mode 8: FSK modulation with shift register data output (SO) The two compare registers are used to generate two different time intervals. The SSI data output selects which compare register is used for the output frequency generation. A '0' level at the SSI data output enables the compare register 1 and a '1' level enables the compare register 2. The compare- and compare mode registers must be programmed to generate the two frequencies via the output toggle flip-flop. The SSI can be supplied with the toggle signal of Timer 2 or any other clock source. The Timer 3 counter is driven by an internal or external clock source. 82 ATAM894 4679D–4BMCU–05/05 ATAM894 Figure 6-65. FSK Modulation T3R Counter 3 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 3 4 0 1 CM31 CM32 0 SO 1 0 T3O 7. Data EEPROM The internal data EEPROM offers 2 pages of 512 bits each. Both pages are organized as 32 × 16 bit words. The programming voltage as well as the write cycle timing is generated on chip. If it is necessary to be compatible with the ROM parts, only the default page must be used with the flash part. Also for compatibility reasons the access to the EEPROM is handled via the MCL (serial interface) as in the corresponding ROM parts. The page select is performed by either writing ''01h'' (page 1) or ''09h'' (page 0) to the EEPROM. Figure 7-1. Block Diagram EEPROM Timing control HV-generator Page 1 VDD VSS EEPROM Address control Page 0 2 x 32 x 16 Mode control SCL I/O control --> write "01h" --> write "09h" 16-bit read/write buffer 8-bit data register SDA 83 4679D–4BMCU–05/05 7.1 Serial Interface The EEPROM uses an MCL-like two-wire serial interface to the microcontroller for read and write accesses to the data. It is considered to be a slave in all these applications. That means, the controller has to be the master that initiates the data transfer and provides the clock for transmit and receive operations. The serial interface is controlled by the microcontroller which generates the serial clock and controls the access via the SCL-line and SDA-line. SCL is used to clock the data into and out of the device. SDA is a bi-directional line that is used to transfer data into and out of the device. The following protocol is used for the data transfers. 7.1.1 Serial Protocol • Data states on the SDA-line changing only while SCL is low • Changes on the SDA-line while SCL is high are interpreted as START or STOP condition • A START condition is defined as high to low transition on the SDA-line while the SCL-line is high • A STOP condition is defined as low to high transition on the SDA-line while the SCL-line is high • Each data transfer must be initialized with a START condition and terminated with a STOP condition. The START condition wakes the device from standby mode and the STOP condition returns the device to standby mode • A receiving device generates an acknowledge (A) after the reception of each byte. This requires an additional clock pulse, generated by the master. If the reception was successful the receiving master or slave device pulls down the SDA-line during that clock cycle. If an acknowledge is not detected (N) by the interface in transmit mode, it will terminate further data transmissions and go into receive mode. A master device must finish its read operation by a non-acknowledge and then send a stop condition to bring the device into a known state. Figure 7-2. MCL Protocol SCL SDA Standby Start condition Data valid Data change Data/ acknowledge valid Stop Standby condition • Before the START condition and after the STOP condition the device is in standby mode and the SDA line is switched as input with pull-up resistor. • The control byte that follows the START condition determines the following operation. It consists of the 5-bit row address, 2 mode control bits and the READ/NWRITE bit that is used to control the direction of the following transfer. A '0' defines a write access and a '1' a read access. 84 ATAM894 4679D–4BMCU–05/05 ATAM894 7.1.1.1 Control Byte Format EEPROM Address Start Start 7.1.2 A4 A3 Control byte A2 Ackn Mode Control Bits A1 A0 Data byte C1 Ackn C0 Data byte Read/ NWrite R/NW Ackn Ackn Stop EEPROM The EEPROM has a size of 2 × 512 bits and is organized as 32 x 16-bit matrix each. To read and write data to and from the EEPROM the serial interface must be used. The interface supports one and two byte write accesses and one to n-byte read accesses to the EEPROM. 7.1.2.1 EEPROM - Operating Modes The operating modes of the EEPROM are defined via the control byte. The control byte contains the row address, the mode control bits and the read/not-write bit that is used to control the direction of the following transfer. A '0' defines a write access and a '1' a read access. The five address bits select one of the 32 rows of the EEPROM memory to be accessed. For all accesses the complete 16-bit word of the selected row is loaded into a buffer. The buffer must be read or overwritten via the serial interface. The two mode control bits C1 and C2 define in which order the accesses to the buffer are performed: High byte – low byte or low byte – high byte. The EEPROM also supports auto increment and auto decrement read operations. After sending the start address with the corresponding mode, consecutive memory cells can be read row by row without transmission of the row addresses. Two special control bytes enable the complete initialization of EEPROM with '0' or with '1'. 7.1.2.2 Write Operations The EEPROM permits 8-bit and 16-bit write operations. A write access starts with the START condition followed by a write control byte and one or two data bytes from the master. It is completed via the STOP condition from the master after the acknowledge cycle. The programming cycle consists of an erase cycle (write “zeros”) and the write cycle (write “ones”). Both cycles together take about 10 ms. 7.1.2.3 Acknowledge Polling If the EEPROM is busy with an internal write cycle, all inputs are disabled and the EEPROM will not acknowledge until the write cycle is finished. This can be used to detect the end of the write cycle. The master must acknowledge polling by sending a start condition followed by the control byte. If the device is still busy with the write cycle, it will not return an acknowledge and the master has to generate a stop condition or perform further acknowledge polling sequences. If the cycle is complete, it returns an acknowledge and the master can proceed with the next read or write cycle. 85 4679D–4BMCU–05/05 Write One Data Byte Start Control byte A Data byte 1 A Stop A Data byte 1 A Data byte 2 Write Two Data Bytes Start Control byte A Stop Write Control Byte Only Start Control byte A Stop Write Control Bytes MSB Write low byte first A4 LSB A3 A2 A1 A0 Row address Byte order LB(R) C1 C0 R/NW 0 1 0 HB(R) MSB Write high byte first A4 LSB A3 A2 A1 Row address Byte order HB(R) A0 C1 C0 R/NW 1 0 0 LB(R) A →acknowledge; HB: high byte; LB: low byte; R: row address 7.1.2.4 86 Read Operations The EEPROM allows byte-, word- and current address read operations. The read operations are initiated in the same way as write operations. Every read access is initiated by sending the START condition followed by the control byte which contains the address and the read mode. When the device has received a read command, it returns an acknowledge, loads the addressed word into the read/write buffer and sends the selected data byte to the master. The master has to acknowledge the received byte if it wants to proceed with the read operation. If two bytes are read out from the buffer the device increments respectively decrements the word address automatically and loads the buffer with the next word. The read mode bits determines if the low or high byte is read first from the buffer and if the word address is incremented or decremented for the next read access. If the memory address limit is reached, the data word address will “roll over” and the sequential read will continue. The master can terminate the read operation after every byte by not responding with an acknowledge (N) by issuing a stop condition. ATAM894 4679D–4BMCU–05/05 ATAM894 Read One Data Byte Start Control byte A Data byte 1 N Stop A Data byte 1 A Data byte 2 Read Two Data Bytes Start Control byte N Stop Read n Data Bytes Start Control byte A Data byte 1 A Data byte 2 A --- Data byte n N Stop Read Control Bytes MSB Read low byte first, address increment A4 LSB A3 A2 A1 A0 Row address Byte order LB(R) HB(R) LB(R+1) HB(R+1) C1 C0 R/NW 0 1 1 --- LB(R+n) MSB Read high byte first, address decrement A4 LSB A3 A2 A1 A0 Row address Byte order HB(R) LB(R) HB(R+n) HB(R-1) LB(R-1) --- C1 C0 R/NW 1 0 1 HB(R-n) LB(R-n) A →acknowledge, N →no acknowledge; HB: high byte; LB: low byte, R: row address 7.1.2.5 Initializing the Serial Interface to the EEPROM To prevent unexpected behavior of the EEPROM and its interface it is good practice to use an initialization sequence after any reset of the circuit. This is performed by writing: Start “FFh” A N Stop to the serial interface. If the EEPROM acknowledges this sequence it is in a defined state. It may be necessary to perform this sequence twice. 87 4679D–4BMCU–05/05 8. Absolute Maximum Ratings Voltages are given relative to VSS. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. All inputs and outputs are protected against high electrostatic voltages or electric fields. However, precautions to minimize the build-up of electrostatic charges during handling are recommended. Reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (e.g., VDD). Parameters Symbol Value Unit Supply voltage VDD –0.3 to +6.5 V Input voltage (on any pin) VIN VSS –0.3 ≤VIN ≤VDD +0.3 V Output short circuit duration tshort indefinite s Operating temperature range Tamb –40 to +85 °C Storage temperature range Tstg –40 to +130 °C Soldering temperature (t ≤10 s) Tsld 260 °C Symbol Value Unit RthJA 135 K/W 9. Thermal Resistance Parameter Thermal resistance (SSO24) 10. DC Operating Characteristics VSS = 0V, Tamb = –40°C to +85°C unless otherwise specified Parameters Test Conditions Symbol Min. VDD VPOR Typ. Max. Unit 6.5 V 0.4 1.0 mA mA mA Power Supply Operating voltage at VDD Active current CPU active fSYSCL = 1 MHz VDD = 1.8V VDD = 3.0V VDD = 6.5V IDD Power down current (CPU sleep, RC oscillator active, 4-MHz quartz oscillator active) fSYSCL = 1 MHz VDD = 1.8V VDD = 3.0V VDD = 6.5V IPD Sleep current (CPU sleep, 32-kHz quartz oscillator active 4-MHz quartz oscillator inactive) VDD = 1.8V VDD = 3.0V VDD = 6.5V ISleep 0.4 0.6 0.8 1.5 2.0 µA µA µA Sleep current (CPU sleep, 32-kHz quartz oscillator inactive 4-MHz quartz oscillator inactive) VDD = 3.0V VDD = 6.5V ISleep 0.3 0.6 1.0 1.8 µA µA Pin capacitance Any pin to VSS CL 7 10 pF 88 0.2 0.3 0.7 40 70 200 150 µA µA µA ATAM894 4679D–4BMCU–05/05 ATAM894 10. DC Operating Characteristics (Continued) VSS = 0V, Tamb = –40°C to +85°C unless otherwise specified Parameters Test Conditions Symbol Min. Typ. Max. Unit VPOR 1.54 1.7 1.88 V VPOR 1.83 2.0 2.20 V Power-on Reset Threshold Voltage POR threshold voltage POR threshold voltage BOT = 1 BOT = 0 POR hysteresis 50 VPOR mV Voltage Monitor Threshold Voltage VM high threshold voltage VDD > VM, VMS = 1 VMThh VM high threshold voltage VDD < VM, VMS = 0 VMThh 3.0 VM middle threshold voltage VDD > VM, VMS = 1 VMThm VM middle threshold voltage VDD < VM, VMS = 0 VMThm VM low threshold voltage VDD > VM, VMS = 1 VMThl VM low threshold voltage VDD < VM, VMS = 0 VMThl VMI VDD = 3V, VMS = 1 VVMI VMI VDD = 3V, VMS = 0 VVMI 1.18 2.77 3.35 3.0 2.6 2.4 2.6 2.0 2.2 2.2 V V 2.9 V V 2.44 V V External Input Voltage 1.3 1.4 1.3 V V All Bi-directional Ports Input voltage LOW VDD = 1.8 to 6.5V VIL VSS 0.2 × VDD V Input voltage HIGH VDD = 1.8 to 6.5V VIH 0.8 × VDD VDD V Input LOW current (switched pull-up) VDD = 2.0V, VDD = 3.0V, VIL = VSS VDD = 6.5V IIL –3 –10 –80 –8 –20 –150 –14 –40 –240 µA µA µA Input HIGH current (switched pull-down) VDD = 2.0V, VDD = 3.0V, VIH = VDD VDD = 6.5V IIH 3 10 60 6 20 100 14 40 160 µA µA µA Input LOW current (static pull-up) VDD = 2.0V VDD = 3.0V, VIL = VSS VDD = 6.5V IIL –30 –80 –300 –50 –160 –700 –98 –320 –1200 µA µA µA Input LOW current (static pull-down) VDD = 2.0V VDD = 3.0V, VIH = VDD VDD = 6.5V IIH 20 80 300 50 160 600 100 320 1000 µA µA µA Input leakage current VIL = VSS IIL 100 nA Input leakage current VIH = VDD IIH 100 nA Output LOW current VOL = 0.2 × VDD VDD = 2.0V VDD = 3.0V, VDD = 6.5V IOL Output HIGH current VOH = 0.8 × VDD VDD = 2.0V VDD = 3.0V, VDD = 6.5V IOH Note: 0.9 3 8 1.8 5 15 3.6 8 22 mA mA mA –0.8 –3 –8 –1.7 –5 –15 –3.4 –8 –24 mA mA mA The Pin BP20/NTE has a static pull-up resistor during the reset-phase of the microcontroller 89 4679D–4BMCU–05/05 11. AC Characteristics Supply voltage VDD = 1.8 to 6.5V, VSS = 0V, Tamb = 25°C unless otherwise specified. Parameters Test Conditions Symbol Min. VDD = 1.8 to 6.5V Tamb = –40 to 85° C tSYSCL VDD = 2.4 to 6.5V Tamb = –40 to 85° C tSYSCL Typ. Max. Unit 500 2000 ns 250 2000 ns 5 MHz Operation Cycle Time System clock cycle Timer 2 input Timing Pin T2I Timer 2 input clock fT2I Timer 2 input LOW time Rise/fall time < 10 ns tT2IL 100 ns Timer 2 input HIGH time Rise/fall time < 10 ns tT2IH 100 ns Timer 3 Input Timing Pin T3I Timer 3 input clock SYSCL/2 fT3I MHz Timer 3 input LOW time Rise/fall time < 10 ns tT3IL 2 tSYSCL ns Timer 3 input HIGH time Rise/fall time < 10 ns tT3IH 2 tSYSCL ns Interrupt request LOW time Rise/fall time < 10 ns tIRL 100 ns Interrupt request HIGH time Rise/fall time < 10 ns tIRH 100 ns Interrupt Request Input Timing External System Clock EXSCL at OSC1, ECM = EN Rise/fall time < 10 ns fEXSCL 0.5 4 MHz EXSCL at OSC1, ECM = DI Rise/fall time < 10 ns fEXSCL 0.02 4 MHz Input HIGH time Rise/fall time < 10 ns tIH 0.1 µs Reset Timing Power-on reset time VDD > VPOR tPOR 1.5 fRcOut1 3.8 5 ms RC-Oscillator 1 Frequency VDD = 2.0 to 6.5V Tamb = –40 to 85° C Stability ∆f/f MHz ±50 % RC-Oscillator 2 - External Resistor Frequency Rext = 180 kΩ Stability VDD = 2.0 to 6.5 V Tamb = –40 to 85° C Stabilization time fRcOut2 4 MHz ∆f/f ±15 % tS 10 µs 4-MHz Crystal Oscillator (Operating Range VDD = 2.2 V to 6.5 V) Frequency fX 4 MHz Start-up time tSQ 5 ms Stability ∆f/f Integrated input/output capacitances (configurable) 90 CIN/COUT programmable CIN COUT –10 10 0, 2, 5, 7, 10 or 12 0, 2, 5, 7, 10 or 12 ppm pF pF ATAM894 4679D–4BMCU–05/05 ATAM894 11. AC Characteristics (Continued) Supply voltage VDD = 1.8 to 6.5V, VSS = 0V, Tamb = 25°C unless otherwise specified. Parameters Test Conditions Symbol Min. Typ. Max. Unit 32-kHz Crystal Oscillator (Operating Range VDD = 2.0V to 6.5V) fX 32.768 kHz Start-up time tSQ 0.5 s Stability ∆f/f Frequency –10 10 ppm CIN COUT 0, 2, 5, 7, 10 or 12 0, 2, 5, 7, 10 or 12 pF pF Crystal frequency fX 32.768 kHz Serial resistance RS 30 Static capacitance C0 1.5 pF Dynamic capacitance C1 3 fF Crystal frequency fX 4.0 MHz Serial resistance RS 40 150 Ω Static capacitance C0 1.4 3 pF Dynamic capacitance C1 3 IWR 600 Integrated input/output capacitances (configurable) CIN/COUT programmable External 32-kHz Crystal Parameters 50 kΩ External 4-MHz Crystal Parameters fF Data EEPROM Operating current during erase/write cycle Endurance Erase-/write cycles Tamb = 85°C Data erase/write cycle time For 16-bit access Data retention time ED ED 9 tDR tDR Tamb = 85°C 13 100 10 0.2 0.2 tPUW Erase-/write cycles, Tamb = 0 to 40°C nEW ms years years tPUR Power-up to write operation µA Cycles Cycles 500000 tDEW Power-up to read operation Program EEPROM 200000 20000 1300 100 1,000 ms ms Cycles Serial Interface SCL clock frequency 11.1 100 fSC_MCL 500 kHz Crystal Characteristics Figure 11-1. Crystal Equivalent Circuit L C1 Equivalent circuit OSCIN SCLIN RS OSCOUT SCLOUT C0 91 4679D–4BMCU–05/05 12. Emulation The basic function of emulation is to test and evaluate the customer's program and hardware in real time. This therefore enables the analysis of any timing, hardware or software problem. For emulation purposes, all MARC4 controllers include a special emulation mode. In this mode, the internal CPU core is inactive and the I/O buses are available via Port 0 and Port 1 to allow an external access to the on-chip peripherals. The MARC4 emulator uses this mode to control the peripherals of any MARC4 controller (target chip) and emulates the lost ports for the application. The MARC4 emulator can stop and restart a program at specified points during execution, making it possible for the applications engineer to view the memory contents and those of various registers during program execution. The designer also gains the ability to analyze the executed instruction sequences and all the I/O activities. Figure 12-1. MARC4 Emulation Emulator target board MARC4 emulator MARC4 emulation-CPU I/O bus Trace memory Port 0 MARC4 target chip CORE I/O control Port 1 Program memory CORE (inactive) Peripherals Port 0 Control logic Port 1 Emulation control SYSCL/ TCL, TE, NRST Application-specific hardware Personal computer 92 ATAM894 4679D–4BMCU–05/05 ATAM894 13. Ordering Information Extended Type Number(1) Program Memory Data-EEPROM Package ATAM894x-TNQY 8 kB Flash 2 × 512 Bit SSO24 Taped and reeled ATAM894x-TNSY 8 kB Flash 2 × 512 Bit SSO24 Tubes Note: 1. x Y Delivery = Hardware revision = Lead-free 14. Package Information 5.7 5.3 Package SSO24 Dimensions in mm 8.05 7.80 4.5 4.3 1.30 0.15 0.15 0.05 0.25 6.6 6.3 0.65 7.15 24 13 technical drawings according to DIN specifications 1 12 93 4679D–4BMCU–05/05 15. Revision History Please note that the following page numbers referred to in this section refer to the specific revision mentioned, not to this document. 94 Revision No. History 4679D-4BMCU-05/05 •Put datasheet in a new template • Lead-free Logo on page 1 added • Figure 5-2 “ROM Map” on page 5 replaced • Section “Interrupt Processing” on page 10 changed • Section “4-MHz Oscillator” on pages 18-19 changed • Section “32-kHz Oscillator” on page 19 changed • Figure 6-2 “Bi-directional Port 1” on page 25 changed • Figure 6-3 “Bi-directional Port 2” on page 26 changed • Figure 6-4 “Bi-directional Port 5” on page 27 changed • Figure 6-6 “Bi-directional Port 4 and Port 6” on page 29 changed • Table “Ordering Information” on page 93 changed 4679C-4BMCU-03/04 • • • • • • • • • • Put datasheet in a new template Figure 1 “Block Diagram” on page 1 changed Table 9 “Peripheral Addresses” on page 23 changed Section “Features” on page 35 changed Table 19 “Timer 2 Output Select Bits” on page 44 changed New heading rows at Table “Absolute Maximum Ratings” on page 86 added Table “Thermal Resistance” on page 86 changed Section “Emulation” on page 90 added Table “Ordering Information” on page 91 deleted Table “Ordering Information” on page 92 changed ATAM894 4679D–4BMCU–05/05 ATAM894 16. Table of Contents Features ..................................................................................................... 1 1 Description ............................................................................................... 1 2 Pin Configuration ..................................................................................... 2 3 Introduction .............................................................................................. 3 4 Differences Between ATAM894 and ATARx90/x92 ............................... 3 4.1 Program Memory ......................................................................................................3 4.2 Configuration Memory ..............................................................................................3 4.3 Data Memory ............................................................................................................3 4.4 Reset Function .........................................................................................................4 5 MARC4 Architecture ................................................................................ 4 5.1 General Description ..................................................................................................4 5.2 Components of MARC4 Core ...................................................................................5 5.3 Master Reset ..........................................................................................................12 5.4 Voltage Monitor ......................................................................................................13 5.5 Clock Generation ....................................................................................................15 5.6 Power-down Modes ................................................................................................21 6 Peripheral Modules ................................................................................ 22 6.1 Addressing Peripherals ..........................................................................................22 6.2 Bi-directional Ports .................................................................................................24 6.3 Universal Timer/Counter/ Communication Module (UTCM) ...................................31 7 Data EEPROM ......................................................................................... 83 7.1 Serial Interface .......................................................................................................84 8 Absolute Maximum Ratings .................................................................. 88 9 Thermal Resistance ............................................................................... 88 10 DC Operating Characteristics ............................................................... 88 11 AC Characteristics ................................................................................. 90 11.1 Crystal Characteristics ..........................................................................................91 12 Emulation ............................................................................................... 92 13 Ordering Information ............................................................................. 93 14 Package Information ............................................................................. 93 95 4679D–4BMCU–05/05 15 Revision History ..................................................................................... 94 16 Table of Contents.................................................................................... 95 96 ATAM894 4679D–4BMCU–05/05 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Regional Headquarters Europe Atmel Sarl Route des Arsenaux 41 Case Postale 80 CH-1705 Fribourg Switzerland Tel: (41) 26-426-5555 Fax: (41) 26-426-5500 Asia Room 1219 Chinachem Golden Plaza 77 Mody Road Tsimshatsui East Kowloon Hong Kong Tel: (852) 2721-9778 Fax: (852) 2722-1369 Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Atmel Operations Memory 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 RF/Automotive Theresienstrasse 2 Postfach 3535 74025 Heilbronn, Germany Tel: (49) 71-31-67-0 Fax: (49) 71-31-67-2340 Microcontrollers 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 La Chantrerie BP 70602 44306 Nantes Cedex 3, France Tel: (33) 2-40-18-18-18 Fax: (33) 2-40-18-19-60 ASIC/ASSP/Smart Cards 1150 East Cheyenne Mtn. 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