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Philips p90ce201 DATASHEETS

INTEGRATED CIRCUITS
DATA SH EET
P90CE201
16-bit microcontroller
Product specification File under Integrated Circuits, IC21
August 1993
16-bit microcontroller P90CE201

CONTENTS

1 FEATURES 2 GENERAL DESCRIPTION 3 ORDERING INFORMATION 4 PINNING INFORMATION
4.1 Pinning
4.2 Pin description 5 CPU FUNCTIONAL DESCRIPTION
5.1 General
5.2 5.2 Programming model and data organization
5.3 Internal and external operation
5.4 Processing states and exception processing
5.5 Stack format
5.6 CPU interrupt processing 6 SYSTEM CONTROL
6.1 Memory mapping
6.2 Interrupt controller
6.3 System Control Registers
6.4 Reset
6.5 Clock circuitry 7 INSTRUCTION SET
7.1 Addressing modes
7.2 Instruction timing 8I
8.1 General
8.2 I2C-bus interface registers 9 UART SERIAL INTERFACE
9.1 General
9.2 Operating modes
9.3 UART registers
2
C-BUS INTERFACE
10 8-BIT GENERAL PORT
10.1 8-bit General Port registers 11 8-BIT AUXILIARY PORT
11.1 8-bit Auxiliary Port registers 12 WATCHDOG TIMER 13 TIMERS
13.1 General
13.2 Timer operating modes
13.3 Timer registers 14 ELECTROMAGNETIC COMPATIBILITY
(EMC) IMPROVEMENTS
15 ELECTRICAL SPECIFICATIONS
15.1 Limiting values
15.2 DC Characteristics
15.3 AC Characteristics 16 REGISTER MAP 17 PACKAGE OUTLINE 18 SOLDERING
18.1 Introduction
18.2 Reflow soldering
18.3 Wave soldering
18.4 Repairing soldered joints 19 DEFINITIONS 20 LIFE SUPPORT APPLICATIONS 21 PURCHASE OF PHILIPS I2C COMPONENTS
August 1993 2
16-bit microcontroller P90CE201

1 FEATURES

• CMOS technology
• Full 68000 software compatibility
• 32-bit internal structure
• 16-bit internal data transfer
• 8-bit access to external ROM/RAM
• External addressing range 16 Mbytes for ROM and
16 Mbytes for RAM
• Unused address pins can be used as quasi-bidirectional ports
• On-chip address decoder for ROM/RAM
• 8 edge triggered programmable interrupts that can also
be used as quasi-bidirectional ports
• Reset control
• Built-in clock generator
2
• 2 fully independent fast I
• UART serial interface (4 modes)
• 3 fully independent 16-bit timers
• Watchdog timer
• 8-bit quasi-bidirectional port, 4-bits with high drive
capability
• EMC optimized layout and pinning
• 64-pin QFP package
C-bus serial interfaces

2 GENERAL DESCRIPTION

The P90CE201 is a member of the P9XCXXX family of highly integrated 16-bit microcontrollers for use in a wide variety of applications. It is fully software compatible with the 68070/68000. The complete set of system functions available on the chip results in reduced system cost. Additionally, its modular design concept permits future extension to the family.

3 ORDERING INFORMATION

EXTENDED
TYPE NUMBER
P90CE201AEB 64 QFP plastic SOT319
Note
1. SOT319-2; 1996 November 28.
August 1993 3
PINS PIN POSITION MATERIAL CODE
PACKAGE CLOCK
FREQUENCY
(1)
TEMPERATURE RANGE
(MHz)
24.0 −25 to 85
(°C)
16-bit microcontroller P90CE201
RESET
XTAL1 XTAL2
GP0-GP7
(1)
PORT
CPU
SYSTEM
CONTROL
WATCHDOG
TIMER
RESET
LOGIC
CLOCK
CSRAMN
ADDRESS DECODER
CSROMN
OCA (31 : 0)
A0-A15
ADDRESS
BUFFER
A16-A23
D0-D7
INTERFACE
OCD (15 : 0)
TIMER 0
TIMER 1
TIMER 2
UART
I C 1
R/WN
DATA
T0
T2
TXD RXD
2
INTN0 ­INTN7
INTERRUPT
CONTROLLER
1. The General Port lines GP5, GP6 and GP7 have alternate functions for Timer 1, SCL1 and SDA1 respectively; see Table 1.
Fig.1 Block diagram
August 1993 4
2
I C 2
SCL2 SDA2
MLB015
16-bit microcontroller P90CE201

4 PINNING INFORMATION

4.1 Pinning

DD2
V
RESET
T0
27
T2
LP0/INTN0 56
55
28
29 A7
A13
54
53
52
V
51
SS2
CSRAMN
50 49
D3
48
D2
47
D4
46
D1
45
D5
44
D0
43
D6
42
A0 D7
41 40
A1
39
A2
38
A10 A3
37
CSROMN
36 35
A4
34
A11
33
A5
30
31
32
A8
A6
MLB003
A9
handbook, full pagewidth
RXD SDA2 SCL2
GP7/SDA1 GP6/SCL1
GP0
GP1
GP2
GP3
GP4
GP5/T1
A23/AP7
A22/AP6 A21/AP5
A20/AP4
XTAL2 XTAL1
V
DD1
V
SS1
TXD
LP6/INTN6
LP7/INTN7
64
63
62 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19
20
21
R/WN
A19/AP3
LP5/INTN5 61
22
23
A18/AP2
A16/AP0
LP4/INTN4 60
P90CE201
24
A17/AP1
LP2/INTN2
LP3/INTN3 59
58
25
26
A15
A14
LP1/INTN1 57
A12
Fig.2 Pin configuration for QFP64.
August 1993 5
16-bit microcontroller P90CE201

4.2 Pin description Table 1 QFP64 package.

MNEMONIC TYPE PIN NO. FUNCTION
RXD I/O 1 Receive Data. RXD is the data input for the UART interface. SDA2 I/O 2 Serial Data 2 (open drain). SDA2 is the data signal for the second
SCL2 I/O 3 Serial Clock 2 (open drain). SCL2 is the clock signal for the second
GP7/SDA1 GP6/SCL1 GP0 GP1 GP2 GP3 GP4 GP5/T1
A23/AP7
to
I/O 4
5 6 7 8 9 10 11
I/O 12 to 15, 21,
22, 24, 23
A16/AP0 A15 to A0 O 25, 26, 28, 27,
34, 38, 32, 30, 29, 31, 33, 35,
37, 39, 40, 42 XTAL2 O 16 Oscillator output. Not connected if an external clock generator is used. XTAL1 I 17 Oscillator input. XTAL1 can also be used as an external clock input if
V
V
DD1
SS1
− 18 Supply voltage. For internal logic, address bus, data bus, RWN,
− 19 Ground. For internal logic, address bus, data bus, RWN, CSRAMN,
R/WN O 20 Read (active HIGH)/Write (active LOW). This controls the direction of
CSROMN O 36 Chip Select ROM (active LOW). This signal selects external ROM. D0 to D7 O 44, 46, 48, 49,
47, 45, 43, 41 CSRAMN O 50 Chip Select RAM (active LOW). This signal enables external RAM. V V
SS2 DD2
− 51 Ground. For all other periphery pins (quiet port).
− 52 Supply voltage. For all other periphery pins (quiet port).
RESET I 53 Reset (active HIGH). Input pin for an external reset. T0 I 54 Timer 0. Input pin for cycle and event counting using Timer 0. T2 I 55 Timer 2. Input pin for cycle and event counting using Timer 2.
2
I
C-bus serial interface.
2
C-bus serial interface.
I General Purpose Port (active HIGH, 3-state). The alternative functions
are as follows. SCL1 is the clock signal for the first I
2
C-bus serial interface. SDA1 is the data signal for the first I2C-bus serial interface. T1 is the input pin for Timer 1.
Address Bus. Upper 8-bits of the address bus (A23 to A16). The unused address bits can be selected as a quasi-bidirectional port (AP).
Address Bus. Lower 16-bits of the address bus.
an external clock generator is used.
CSRAMN, CSROMN, XTAL1 and XTAL2.
CSROMN, XTAL1 and XTAL2.
data flow.
Data Bus. 8-bit data bus.
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16-bit microcontroller P90CE201
MNEMONIC TYPE PIN NO. FUNCTION
LP0/INTN0 LP1/INTN1 LP2/INTN2 LP3/INTN3 LP4/INTN4 LP5/INTN5 LP6/INTN6 LP7/INTN7
TXD O 64 Transmit Data. TXD is the data output for the UART serial interface.
I/O 56
57 58 59 60 61 62 63
Latched Interrupt inputs (active LOW). A LOW level of ≥ 1 clock pulse will be stored as a pending interrupt request. Priority levels are programmable. Unused interrupt inputs can be used as a quasi-bidirectional port (LP).
August 1993 7
16-bit microcontroller P90CE201

5 CPU FUNCTIONAL DESCRIPTION

5.1 General

The CPU of the P90CE201 is software compatible with the 68000, consequently programs written for the 68000 will run on the P90CE201 unchanged. However, for certain applications the following differences between the processors should be noted:
• The initialization of the System Control Registers.
• Differences exist in the address error exception
processing since the P90CE201 can provide full error recovery.
• The timing is different because of the P90CE201’s new architecture and technology. The instruction execution timing is completely different for the same reason.
31 16 15 8 7 0
handbook, full pagewidth

5.2 5.2 Programming model and data organization

The programming model is identical to that of the 68000 and is shown in Fig.3. It contains seventeen 32-bit registers, a 32-bit Program Counter and a 16-bit Status Register. The first eight registers (D0 to D7) are used as data registers for byte, word and long-word operations. The second group of registers (A0 to A6) and the System Stack Pointer (A7) can be used as software stack pointers and base address registers. In addition, these registers can be used for word and long-word address operations. All seventeen registers can be used as Index Registers.
The P90CE201 supports 8, 16 and 32-bit integer data, BCD data 32-bit addresses. Each data type is arranged in memory as shown in Fig.4.
DO D1 D2
Eight
D3
Data
D4
Registers
D5 D6 D7
31 16 15 0
USER STACK POINTER
SUPERVISOR STACK POINTER
31 0
MCD504
Fig.3 Programming model.
August 1993 8
15 8 7 0
SYSTEM
BYTE
USER
BYTE
A0 A1 A2 A3 A4 A5 A6
A7
Seven Address Registers
Two Stack Pointers
Program Counter
Status Register
16-bit microcontroller P90CE201
bit
(a) Bit data (1 Byte = 8 bits).
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0bit MSB BYTE 0
BYTE 2
(b) Integer data (1 Byte = 8 bits).
1514131211109876543210bit
MSB WORD 0
(c) Word data (16 bits).
1514131211109876543210bit
MSB HIGH ORDER
LONG WORD 0
LONG WORD 1
LONG WORD 2
(d) Long-word data (32 bits).
276543 1 0
LSB
WORD 1 WORD 2
BYTE 1 BYTE 3
LOW ORDER LSB HIGH ORDER LOW ORDER HIGH ORDER LOW ORDER
LSB
1514131211109876543210bit
MSB HIGH ORDER
1514131211109876543210bit
MSB LSB
ADDRESS 0
ADDRESS 1
ADDRESS 2
(e) Addresses (1 address =32 bits).
BCD 0 BCD 1 BCD 4 BCD 5
(f) BCD data (2 BCD digits = 1 Byte).
LOW ORDER LSB HIGH ORDER LOW ORDER HIGH ORDER LOW ORDER
Fig.4 Memory data organization.
August 1993 9
BCD 2 BCD 3 BCD 6 BCD 7
MCD505
16-bit microcontroller P90CE201
handbook, full pagewidth
T – S – – 121110 – – – X N Z V C
Trace Mode
Supervisor
State
Interrupt
Mask
Fig.5 Status Register.

5.3 Internal and external operation

The P90CE201 operates with an internal clock frequency of half the oscillator frequency (f
/2). Each internal clock
OSC
cycle is divided into 2 states. A non-access machine cycle has 3 clock cycles or 6 states (S0 to S5). A minimum bus cycle normally consists of 3 clock cycles (6 states). When data transfer has not yet been terminated, wait states (SW) are inserted in multiples of 2. For external memory access, 2 wait states (bus states SB) are added automatically.

5.4 Processing states and exception processing

The CPU is always in one of three processing states: normal, exception or halted.
The normal processing state is that associated with instruction execution; the memory references are to fetch instructions and operands and to store results. A special case of the normal state is the stopped state which the processor enters when a STOP instruction is executed. In this state the CPU makes no further memory references.
048101315BIT
Carry
Overflow
Zero
Negative
Extend
MCD506
The halted processing state is an indication of a catastrophic hardware failure. For example, if during exception processing of a bus error another bus error occurs, the CPU assumes that the system is unusable and halts. Only an external reset can restart a halted processor. Note that a CPU in the stopped state is not in the halted state or vice versa.
The processor can work in the “user” or “supervisor” state determined by the state of the S-bit in the Status Register. Accesses to the on-chip peripherals are achieved in the supervisor state.
All exception processing is performed in the supervisor state once the current content of the Status Register has been copied. The exception vector number is then determined and copies of the Status Register, the Program Counter value and the format/vector number are saved on the supervisor stack using the Supervisor Stack Pointer. Finally, the contents of the exception vector location is fetched and loaded into the Program Counter.
The exception processing state is associated with interrupts, trap instructions, tracing and other exceptional conditions. The exception may be generated internally by an instruction or by an unusual condition arising during the execution of an instruction. Externally, exception processing can be forced by an interrupt or a reset.
August 1993 10
16-bit microcontroller P90CE201
5.4.1 EXCEPTION VECTORS
Exception vectors are memory locations from which the CPU fetches the address of a routine that will handle that exception. All exception vectors are 2 words long (see Fig.6) except for the reset vector which is made up of 4 words, containing the Program Counter (PC) and the Supervisor Stack Pointer (SSP). All exception vectors are contained in the supervisor data space.
A vector number is an 8-bit number that, when multiplied by 4, gives the address of an exception vector. Vector numbers are generated internally. The memory map for the exception vectors is given in Table 2.
handbook, halfpage
Word 0 Word 1
NEW PROGRAM COUNTER (HIGH)
NEW PROGRAM COUNTER (LOW)
MCD509
Fig.6 Exception vector format.
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16-bit microcontroller P90CE201
Table 2 Exception vector assignment.
VECTOR NO. DEC HEX ASSIGNMENT
0 0 000 Reset: initial SSP 1 4 004 Reset: initial PC 2 8 008 Bus error 3 12 00C Address error 4 16 010 Illegal instruction 5 20 014 Zero divide 6 24 018 CHK instruction 7 28 01C TRAPV instruction 8 32 020 Privilege violation 9 36 024 Trace 10 40 028 Line 1010 emulator 11 44 02C Line 1111 emulator 12 48 030 Unassigned, reserved 13 (note 1) 52 034 Unassigned, reserved 14 56 038 Format error 15 60 03C Uninitialized interrupt vector 16 to 23 (note 1) 64 − 92 040 − 05C Unassigned, reserved 24 96 060 Spurious interrupt 25 100 064 Level 1 on-chip interrupt autovector 26 104 068 Level 2 on-chip interrupt autovector 27 108 06C Level 3 on-chip interrupt autovector 28 112 070 Level 4 on-chip interrupt autovector 29 116 074 Level 5 on-chip interrupt autovector 30 120 078 Level 6 on-chip interrupt autovector 31 124 07C Level 7 on-chip interrupt autovector 32 to 47 128 − 188 080 − 0BC TRAP instruction vectors 48 to 63 (note 1) 192 − 252 0C0 − 0FC Unassigned, reserved 64 to 255 256 − 1020 100 − 3FC User interrupt vectors
Note
1. Vectors 12, 13, 16 to 23 and 48 to 63 are reserved for future enhancements. No user peripheral devices should be
assigned to these numbers.
August 1993 12
16-bit microcontroller P90CE201
5.4.2 MULTIPLE EXCEPTIONS
As two or more exceptions can occur simultaneously, exceptions are grouped in order of priority; as is shown in Table 3.
5.4.3 I
NSTRUCTION TRAPS
Traps are exceptions caused by instructions arising either from CPU recognition of abnormal conditions during instruction execution or from instructions whose normal behaviour is to cause traps.
Some instructions are used specifically to generate traps. The TRAP instruction always forces an exception, and is useful for implementing system calls for user programs. The TRAPV and CHK instructions force an exception if the user program detects a run-time error, possibly an arithmetic overflow or a subscript out of bounds. The signed divide (DIVS) and unsigned divide (DIVU) instructions will force an exception if a divide-by-zero operation is attempted.
5.4.4 I
LLEGAL AND UNIMPLEMENTED INSTRUCTIONS
Illegal instruction is the term used to refer to any word that is not the first word of a legal instruction. During instruction execution, if such an instruction is fetched, an illegal instruction exception occurs. Words with bits 15 to 12 equal to 1010 or 1111 are defined as unimplemented instructions and separate exception vectors are allocated to these patterns for efficient emulation. This facility allows the operating system to detect program errors, or to emulate unimplemented instructions in software.
• STOP
• RESET
• RTE
• MOVE TO SR
• AND (word) immediate to SR
• EOR (word) immediate to SR
• OR (word) immediate to SR
• MOVE USP.
5.4.6 T
RACING
The CPU includes a facility to trace instructions one by one to assist in program development. In the trace state, after each instruction is executed, an exception is forced so that a debugging program can monitor execution of the program under test.
The trace facility uses the T-bit in the supervisor part of the Status Register. If the T-bit is cleared, tracing is disabled and instructions execute normally. If the T-bit is set at the beginning of the execution of an instruction, a trace exception will be generated after that instruction is executed. If the instruction is not executed, either because of an interrupt, or because the instruction is illegal or privileged, the trace exception does not occur. Also, the trace exception does not occur if the instruction is aborted by a reset, bus error, or address error exception. If the instruction is executed and an interrupt is pending, the trace exception is processed before the interrupt. If the execution of an instruction forces an exception, the forced exception is processed before the trace exception.
5.4.5 P
RIVILEGE VIOLATIONS
To provide system security, various instructions are privileged and any attempt to execute one of the privileged and any attempt to execute one of the privileged instructions while the CPU is in the user state causes an
As an extreme illustration of the above rules, consider the arrival of an interrupt during the execution of a TRAP instruction while tracing is enabled. First the trap exception is processed, then the trace exception, and finally the interrupt is processed. Instruction execution resumes in the interrupt handling routine.
exception. The privileged instructions are:
Table 3 Exception grouping and priority.
GROUP EXCEPTION PROCESSING
0 RESET, ADDRESS ERROR
Exception processing begins at the next machine cycle.
BUS ERROR
1 TRACE, INTERRUPT,
Exception processing begins before the next instruction.
ILLEGAL, PRIVILEGE
2 TRAP, TRAPV, CHK, ZERO,
DIVIDE, FORMAT ERROR
Exception processing is started through normal instruction execution.
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16-bit microcontroller P90CE201

5.5 Stack format

The stack format for exception processing is similar to the 68010 (rather than the 68000) although the information stored is not the same due to the different architecture. To handle this format the P90CE201 differs from the 68000 in that:
• The stack format has changed.
• The minimum number of words put into, or restored from, the stack is 4 (68010 compatible; not 3 as with the 68000).
• The RTE instruction decides (with the aid of the 4 format bits) whether or not more information has to be restored. The
P90CE201 long format is used for bus error and address error exceptions; all other exceptions use the short format.
• If another format code, other than one of the two listed above, is detected during the restore action, a Format Error occurs.
If the user wants to finish the instruction in which the bus or address error occurred, the P90CE201 format must be used on RTE. If no changes to the stack are required during exception processing, the stack format is transparent to the user.
5.5.1 L
handbook, 4 columns
ONG AND SHORT STACK FORMATS
SP
Long Stack Format
FORMAT (4 bits) VECTOR NUMBER
SR PCH PCL
SSW
MM INTERNAL INFORMATION INTERNAL INFORMATION
TPDH TPDL TPFH
TPFL DBINH DBINL
IR
IRC
INTERNAL INFORMATION
Short Stack Format
MCD512
SR Status Register. PCH/PCL Program Counter High/Low Word. FORMAT Indicating either a short stack
(only the first 4 words), or the long stack format for bus and address error exceptions. See Fig.9.
VECTOR NUMBER The vector number of the
exception in the vector table; e.g. 2 for a bus error and 3 for an
address error. See Fig.9. SSW Special Status Word; see Fig.8. MM Current Move Multiple Mask. TDPH/TDPL In the event of a faulty write cycle,
the data can be found here. TPFH/TPFL The address used during the faulty
bus cycle. DBINH/DBINL Data that has been read prior to
the faulty cycle can in some cases
be found here. IR Holds the current instruction
being executed. IRC Holds either the present
instruction being executed or the
prefetched instruction.
Fig.7 Stack format.
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16-bit microcontroller P90CE201
5.5.2 THE SPECIAL STATUS WORD (SSW)
handbook, full pagewidth
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0bit
RR
IF DF RM HB BY RW HW LC
*
***
Fig.8 Special Status Word.
Table 4 Description of SSW.
SYMBOL BIT FUNCTION
RR SSW.15 Rerun. By default this bit is a logic 0. If set to a logic 1, the CPU will not re-run the
faulty bus cycle on return from exception (RTE).
− SSW.14 Undefined, reserved
IF SSW.13 The faulty cycle was an instruction fetch. DF SSW.12 The faulty cycle was a data fetch. RM SSW.11 The error occurred during a read-modify-write cycle. HB SSW.10 High Byte BY SSW.9 The faulty cycle was a byte transfer.
RW SSW.8 Read/Write cycle HW SSW.7 High Word
LC SSW.6 The faulty cycle was during a long-word access.
− SSW.5 Undefined, reserved
− SSW.4 Undefined, reserved
− SSW.3 Undefined, reserved
FC2 FC1 FC0
SSW.2 SSW.1 SSW.0
Function Code. These three bits hold the internal function code during the faulty bus cycle. The function codes are the same as for the 68000 and affect the status of the CPU during the faulty bus cycle. See Table 5.
FC
FC
FC
1
2
0
MCD513
Table 5 Internal function codes.
FC2 FC1 FC0 ADDRESS SPACE
0 0 0 Reserved 0 0 1 User data 0 1 0 User program 0 1 1 Reserved 1 0 0 Reserved 1 0 1 Supervisor data 1 1 0 Supervisor program 1 1 1 Interrupt acknowledge
August 1993 15
16-bit microcontroller P90CE201
1514131211109876543210bit
VECTOR NUMBERFORMAT CODE 0 0 0 0
FORMAT CODE either 0000 or 1111
INFORMATION STACKED Short Format (4 words) 68070 Format (17 words)
Fig.9 Vector number and format code.

5.6 CPU interrupt processing

An Interrupt Controller handles all interrupts, solves any priority problems and passes the highest level interrupt to the CPU. The general interrupt handling mechanism and the Interrupt Controller are described in section 6.2.
The CPU interrupt handling follows the same basic rules as in the 68000. However, the following changes have been made to simplify system development:
• Interrupts with a priority level equal to or less than the priority level actually running will not be accepted.
• During the acknowledge cycle of an interrupt, the IPL bits of the Status Register are set to the priority level of the acknowledged interrupt. An exception to this is when the IM bit in SYSCON2 is a logic 0. In this case level 7 is loaded into the Status Register. See section 6.1.2.
MCD514
The processor then starts normal exception processing by saving the format word, Program Counter, and Status Register in the supervisor stack. The value of the vector in the format word is either supplied externally by the requesting device or is an internally generated vector number multiplied by four (format is all zeros). The Program Counter value is the address of the instruction that would have been executed if the interrupt had not been present. Then the interrupt vector contents are fetched and loaded into the Program Counter. The interrupt handling routine starts with normal instruction execution.
Priority level 7 is a special case; it can only be detected if the priority level was set to a lower value in between.
If the priority of the interrupt pending is greater than the current processor priority then:
• The exception processing sequence is started.
• A copy of the Status Register is saved.
• The privilege level is set to supervisor state.
• Tracing is suppressed.
• The priority level of the processor is set to that of the
interrupt being acknowledged.
The processor then gets the vector number from the interrupting device, classifies it as an interrupt acknowledge, and displays the interrupt level number being acknowledged on the address bus.
If autovectoring is requested by the interrupting device, the processor internally generates a vector number that corresponds to the interrupt level number.
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16-bit microcontroller P90CE201

6 SYSTEM CONTROL

6.1 Memory mapping

The P90CE201 accesses the external ROM and RAM via 8 data lines and up to 24 address lines. Data access to or from the memories is bytewise. The data will be split or restructured internally to match the internal 16-bit data format. The upper byte (bits 15 to 8) of the data is taken from the even address, the lower byte (bits 7 to 0) from the odd address (MSB address + 1).
For external memory control the device provides the R/WN signal together with chip enable signals for ROM (CSROMN) and RAM (CSRAMN). CSROMN is activated in the internal address range 0H to FFFFFFH. The CSRAMN signal is activated in the internal address range 1000000H to 1FFFFFFH. In the external world RAM and ROM are wired in parallel with a maximum address range of 16 Mbytes each. If the larger memory of RAM or ROM is smaller than 16 Mbytes the unused address pins can be used as port pins. The advantages of this addressing scheme are:
• Maximum flexibility for RAM and ROM sizes.
• The full physical memory size can be used without any
restrictions.
• The minimum number of address pins are used. The validity of data is signalled to the CPU by the internal
signal DTACKN. This signal is generated internally after a programmable delay (wait states). By programming the number of wait cycles the user can adapt the program execution times to his memory access times. After reset the delay for the DTACKN signal is set to its maximum value. Programming the number of wait cycles is described in section 6.3.2.
handbook, full pagewidth
A0 A23
D0 D7
CSRxMN
(Additional
Wait States)
S0 S1 S2 S3 SB SB S4 S5 S0 S1 S2 S3 SB SB S4 S5 S0 S1
PHI1
R/WN
Fig.10 External memory interface timing - Word access.
August 1993 17
byte readbyte write
MLB004
16-bit microcontroller P90CE201
handbook, full pagewidth
PHI1
A0 A23
D0 D7
R/WN
CSRxMN
(Additional
Wait States)
S0 S1 S2 S3 SB SB S4 S5 S0 S1 S2 S3 SB SB S4 S5 S0 S1
byte readbyte write
MLB005
Fig.11 External memory interface timing - Byte access.
August 1993 18
16-bit microcontroller P90CE201

6.2 Interrupt controller

An interrupt controller handles all internal and external interrupts. It passes the interrupt with the highest level priority to the CPU.
The following interrupt requests are generated by the on-chip peripherals.
• I2C1
• I2C2
• UART receiver
• UART transmitter
• Timer 2
• Timer 1
• Timer 0.
The following interrupt requests are sent via external pins.
• INTN0 to INTN7
6.2.1 I
NTERRUPT ARBITRATION
The priority level of all interrupts are programmable and each may be allocated a value between 0 and 7. Level 7 has the highest priority, level 0 disables the corresponding interrupt source. In the event of interrupt requests of equal priority level occurring at the same time, then a hardware mechanism gives the following order.
• INTN7
• INTN6
• INTN5
• INTN4
• INTN3
• INTN2
• INTN1
• INTN0
• Timer 2
• Timer 1
• Timer 0
• UART receiver
• UART transmitter
• I2C2
• I2C1.
The execution of interrupt routines may be interrupted by another higher priority level interrupt request (nested interrupts). In the 68070 mode (SYSCON2.7 = 1), when an interrupt is serviced by the CPU, the corresponding level is loaded into the Status Register. This prevents the current interrupt from getting interrupted by another interrupt request with the same or lower priority level. If SYSCON2.7 = 0, priority level 7 will always be loaded into the Status Register and therefore the current interrupt cannot be interrupted by any other interrupt request.
6.2.2 A
CKNOWLEDGE AND INTERRUPT VECTORS
When the CPU is ready to service a particular interrupt request, it initiates an “interrupt acknowledge cycle” in order to obtain the interrupt vector from the requesting device. When the device recognizes that its interrupt request has been accepted it either provides an 8-bit interrupt vector together with an internal DTACKN signal (vector mode), or it asserts an internal AVN signal and the interrupt vector is calculated from the interrupt level.
6.2.3 E
XTERNAL LATCHED INTERRUPTS
INTN7 to INTN0 are 8 external interrupt inputs; each triggered on the falling edge of the input. Their priority levels as well as their interrupt vectors are programmable.
As an alternative function INTN7 to INTN0 may be used as I/O ports. When an interrupt pin is programmed as a port, the corresponding bit in the Port Control Register LPCRH (or LPCRL) is used for port I/O. A read from either of these two registers reads the value from the corresponding bit in the Port Control Register. A read from the Port Pad Control Register LPPH (or LPPL) reads the value from the corresponding port input pin. A write to LPCRH (or LPCRL) or to LPPH (or LPPL) writes the value to the corresponding port register, from where it is driven to the corresponding port pin.
The port function is configured as a quasi-bidirectional port. A bit is set to input mode by writing a logic 1 to the corresponding Port Control Register bit. This drives a “weak” logic 1 to the corresponding output pin, which can be overwritten by an external signal.
In the following register descriptions “n” represents the external interrupt number (0 to 7), its associated registers are identified using the same number.
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16-bit microcontroller P90CE201
6.2.4 LATCHED INTERRUPT REGISTER n (LIRn)
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
INTNC1 INTNC0 AVN − PIR IPL2 IPL1 IPL0
Fig.12 Latched Interrupt Register n (LIRn).
Table 6 Description of LIRn bits.
SYMBOL BIT FUNCTION
INTNC1 INTNC0
AVN LIRn.5 Autovector. When AVN = 0; INTNn is an autovectored interrupt and the processor
− LIRn.4 Not used; reserved
PIR LIRn.3 Pending Interrupt Request. If PIR = 1; then a valid interrupt request has been
IPL2 IPL1 IPL0
LIRn.7 LIRn.6
LIRn.2 LIRn.1 LIRn.0
Interrupt Control. These two bits enable/disable the external interrupt INTNn, or select the pin as an I/O port. See Table 7.
calculates the appropriate vector from a fixed vector table. This is also the default value. When AVN = 1; INTNn is a vectored interrupt and the peripheral must provide an 8-bit vector number.
detected. It is automatically reset by the interrupt acknowledge cycle from the CPU. If PIR = 0; there is no pending interrupt request; this is also the default value. PIR can be set or reset by software by writing a logic 1 or logic 0 respectively to PIRn.
Interrupt Priority Level. These three bits select the interrupt priority level for the external interrupt INTNn. See Table 8.
Table 7 Interrupt INTNn control.
INTNC1 INTNC0 INTERRUPT CONTROL
0 0 Interrupt disabled; this is also the default value. 0 1 interrupt enabled 1 0 Interrupt pin is selected as an I/O port. 1 1 Reserved
Table 8 Selection of interrupt priority level.
IPL2 IPL1 IPL0 PRIORITY LEVEL
0 0 0 Interrupt inhibited; this is also the default value. 0 0 1 Level 1 0 1 0 Level 2 0 1 1 Level 3 1 0 0 Level 4 1 0 1 Level 5 1 1 0 Level 6 1 1 1 Level 7
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16-bit microcontroller P90CE201
6.2.5 LATCHED INTERRUPT VECTOR n (LIVn)
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
IV.7 IV.6 IV.5 IV.4 IV.3 IV.2 IV.1 IV.0
Fig.13 Latched Interrupt Vector n (LIVn).
Table 9 Description of LIVn bits.
SYMBOL BIT FUNCTION
IV.7 to IV.0 LIVn.7 to LIVn.0 8-bit interrupt vector number. The default value of this register is 0FH.
6.2.6 L
6.2.7 LATCHED PORT CONTROL REGISTER LOW (LPCRL)
ATCHED PORT CONTROL REGISTER HIGH (LPCRH)
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
INTN7 − INTN6 − INTN5 − INTN4 −
Fig.14 Latched Port Control Register High (LPCRH).
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
INTN3 − INTN2 − INTN1 − INTN0 −
Fig.15 Latched Port Control Register Low (LPCRL).
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16-bit microcontroller P90CE201
6.2.8 LATCHED PORT PIN REGISTER HIGH (LPPH)
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
INTN7 − INTN6 − INTN5 − INTN4 −
Fig.16 Latched Port Pin Register High (LPPH).
6.2.9 L
ATCHED PORT PIN REGISTER LOW (LPPL)
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
INTN3 − INTN2 − INTN1 − INTN0 −
Fig.17 Latched Port Pin Register Low (LPPL).
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16-bit microcontroller P90CE201

6.3 System Control Registers

The P90CE201 has two System Control Registers SYSCON1 and SYSCON2 which allow system parameters to be selected.
6.3.1 S
handbook, full pagewidth
YSTEM CONTROL REGISTER 1 (SYSCON1)
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0bit
Fig.18 System Control Register 1 (SYSCON1).
Table 10 Description of SYSCON1 bits.
SYMBOL BIT FUNCTION
− SYSCON1.15
These eight bits are not used.
to
SYSCON1.8
NROD2 NROD1 NROD0
SYSCON1.7 SYSCON1.6 SYSCON1.5
These three bits select the access time for the ROM area. After a reset operation these bits are logic 0’s. See Table 11.
− SYSCON1.4 not used
− SYSCON1.3 not used
NRAD2 NRAD1 NRAD0
SYSCON1.2 SYSCON1.1 SYSCON1.0
These three bits select the access time for the RAM area. After a reset operation these bits are logic 0’s. See Table 11
NRAD1NROD2 NROD1 NROD0 NRAD0NRAD2
MLB011
Table 11 Selection of memory access times for ROM and RAM areas.
NROD2 NROD1 NROD0 NRAD2 NRAD1 NRAD0 24 20 16 12
ADD WAIT
STATES
f
XTAL
(MHz)
0 0 0 8 185 235 310 435 ns 0 0 1 4 101 135 185 268 ns 0 1 0 2 60 85 122 185 ns 0 1 1 0 18 35 60 101 ns
Notes
1. 1 internal clock cycle contains 2 wait states.
2. All other states are undefined and reserved.
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UNIT
16-bit microcontroller P90CE201
6.3.2 SYSTEM CONTROL REGISTER 2 (SYSCON2)
handbook, full pagewidth
2
I C2
CON
2
I C1 CON
915 14 13 12 11 10bit
T2
PSBPCLK1PSBPCLK
SEL
254 3876
2
TOPSTOED
IM WD
0
I C1
PO
TOED
0
1
1
T1PST1
PO
MLB012
0
Fig.19 System Control Register 2 (SYSCON2).
Table 12 Description of SYSCON2 bits.
SYMBOL BIT FUNCTION
− SYSCON2.15
These three bits are not used.
to
SYSCON2.13
I2C2CON SYSCON2.12 This bit along with the three bits CR0, CR1 and CR2 held in the Serial Control
Register (S2CON), are used to select the bitrate of the I2C-bus 2 interface. If I2C2CON = 0; the interface operates with a high bitrate. If I2C2CON = 1; the interface operates with a low bitrate.
2
I
C1CON SYSCON2.11 This bit along with the three bits CR0, CR1 and CR2 held in the Serial Control
Register (S1CON), are used to select the bitrate of the I
2
C-bus 1 interface. If I2C1CON = 0; the interface operates with a high bitrate. If I2C1CON = 1; the interface operates with a low bitrate.
T2SEL SYSCON2.10 This bit selects the frequency of the clock for Timer 2. If T2SEL = 0; the timer
operates at a frequency of f
/2. If T2SEL = 1; the timer operates at a frequency
XTAL
of BPCLK/4.
PSBPCLK1 PSBPCLK0
SYSCON2.9 SYSCON2.8
These two bits control the prescaler for the basic peripheral clock. See Table 13.
IM SYSCON2.7 If IM = 0; level 7 is loaded into the Status Register during interrupt processing to
prevent the CPU from being interrupted by another interrupt source. If IM = 1; the current interrupt level is loaded into the Status Register allowing nested interrupts.
WD SYSCON2.6 This bit enables or disables the Watchdog timer for bus error (internal) detection.
If WD = 0; the timer is disabled. If WD = 1; the timer is enabled for bus error detection. If no acknowledge has been sent by the addressed device after 128 × 16 internal clock cycles the on-chip bus error signal is activated.
2
I
C1PO SYSCON2.5 The state of this bit determines whether general port pins GP.7/SDA1 and
GP.6/SCL1 are used as port pins or in their I2C-bus function. When I2C1P0 = 0; the port function is selected. When I2C1P0 = 1; the I2C-bus is selected.
T0PS SYSCON2.4 This bit enables or disables the prescaler for Timer 0. If T0PS = 0; the prescaler is
T0ED1 T0ED0
SYSCON2.3 SYSCON2.2
disabled and the timer operates at a frequency of f is enabled and the timer operates at a frequency of f
These two bits select which transition at the external input will trigger an increment of Timer 0. See Table 14.
/2. If T0PS = 1; the prescaler
XTAL
/32.
XTAL
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