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ECE 371 Microprocessor Interfacing. Unit 2 - Introduction to the MC9S12DP256B Microcontroller. 16-bit Microcontroller Family (Partial List). • MC9S12D64 MC9S12DG128B MC9S12DP256B (our chip) MC9S12DP512. Product Numbering System. MC 9 S12 DP 256 B Status. Memory type. - 9:flash.
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ECE 371Microprocessor Interfacing Unit 2 - Introduction to the MC9S12DP256B Microcontroller
16-bit Microcontroller Family (Partial List) • MC9S12D64 • MC9S12DG128B • MC9S12DP256B (our chip) • MC9S12DP512
Product Numbering System MC 9 S12 DP 256 B Status Memory type - 9:flash Core type Family Approximate memory size Flash revision
68HC12 References • http://www.freescale.com • products -> microcontrollers -> 16 bit microcontrollers • documentation -> microcontrollers -> 16 bit microcontrollers • Lab Computers – Files
INTERNAL FEATURES OF MCS912DP256B (PARTIAL LIST) MEMORY A/D CONVERTER I/O PORTS PULSE-WIDTH MODULATON OUTPUTS SERIAL I/O WATCH DOG TIMER TIMER CONTROLLER AREA NETWORK (CAN) SIGNALS PULSEACCUMULATOR
INTERNAL MEMORY OF MCS912DP256B • 12 K BYTES OF RAM (PROGRAM CODE, VARIABLES, AND STACK) • 4K BYTES OF EEPROM (SYSTEM DATA) • 256K BYTES OF FLASH EEPROM (PROGRAM CODE) • ALSO 2K BYTES FOR REGISTERS
Registers Programmable Memory Manager Internal SRAM CPU Internal EEPROM 16-bit Address 64K Internal Flash External SRAM 256K
CONNECTIONS TO THE OUTSIDE WORLD 112 PINS ON MC9S12DP256B CHIP PORTS A - 8 BITS B - 8 BITS E - 8 BITS H - 8 BITS J - 4 BITS K - 7 BITS M - 8 BITS P - 8 BITS S - 8 BITS T - 8 BITS AD0 - 8 BITS AD1 - 8 BITS TOTAL: 91 I/O BITS 13 PINS FOR INPUT VOLTAGES AND GROUND 6 PINS FOR CLOCK INPUTS AND RESET 2 OTHER PINS (BKGD, TEST) NOTE: MOST PINS HAVE MULTIPLE FUNTIONS
ALTERNATE FUNCTIONS OF PORT PINS PORTS A AND B - EXTERNAL ADDRESS/DATA BUS PORT E - 8 BITS - CONTROL SIGNALS, MODE SELECTION, INTERRUPT REQUESTS, PORT T - 8 BITS - TIMER PINS PORT S - 8 BITS - ASYNCHRONOUS SERIAL I/O (SCI) PINS PORT H - 8 BITS - SYNCHRONOUS SERIAL I/O (SPI) PINS; INTERRUPT REQUESTS PORT M - 8 BITS SPECIAL SERIAL I/O (BDLC, CAN) PORT J - 4 BITS - INTERRUPT REQUESTS; CAN SIGNALS
MORE ALTERNATE FUNCTIONS OF PORT PINS PORT P - 8 BITS - PULSE WIDTH MODULATION (PWM) OUTPUTS; INTERRUPT REQUESTS PORT K - 7 BITS - ADDRESS LINES A19-A14 FOR EXPANDED (EXTERNAL ACCESS MODE) PORT AD0 - 8 BITS - INPUTS TO A/D CONVERTER 0 PORT AD1 - 8 BITS - INPUTS TO A/D CONVERTER 1
Operating Modes • No External Addresses • No External Data Buses • Single Chip Stand Alone Mode • Port A – General Purpose I/O • Port B – General Purpose I/O • Selected by: - BKGD =1, MODB = 0, MODA = 0 • Operating Modes are Sensed at Reset Normal Single-Chip Mode
Operating Modes Normal Expanded Wide Mode • Multiplexed 16-bit Address/16-bit Data Bus • Port A – High Address and Data Bits • Port B – Low Address and Data Bits • ADDR[7:0] and DATA[7:0] • Control Signals: R/W (from PE2) ECLK (from PE4) • Selected by: - BKGD =1, MODB = 1, MODA = 1
Operating Modes Normal Expanded Narrow Mode • Multiplexed 16-bit Address/8-bit Data Bus • Port A – High Address and All 8 Data Bits- ADDR[15:8] and DATA[7:0] • Port B – Low Address • ADDR[7:0] • Control Signals: R/W (from PE2) ECLK (from PE4) • Selected by: - BKGD =1, MODB = 0, MODA = 1
MULTIPLEXED WIDE BUS ADDR7 - ADDR0/ DATA7 - DATA0 PB7 - PB0 ADDR 15 - ADDR8/ DATA15 - DATA8 PA7 - PA0 PE2 R/W (EXTERNAL BUS CLOCK) PE4 ECLK LSTRB PE3
MULTIPLEXED NARROW BUS ADDR7 - ADDR0 PB7 - PB0 PA7 - PA0 ADDR 15 - ADDR8/ DATA7 - DATA0 PE2 R/W PE4 ECLK
Access Type vs. Bus Control Pins Table 12-5 Access Type vs. Bus Control Pins /LSTRB A0 R/W Type of Access 1 0 1 8-bit read of an even address 0 1 1 8-bit read of an odd address 1 0 0 8-bit write of an even address 0 1 0 8-bit write of an odd address 0 0 1 16-bit read of an even address 1 1 1 XXX 0 0 0 16-bit write to an even address 1 1 0 XXX
Interface to 16-bit Data Bus A17 .. A1 A17 .. A1 /cs1 cs2 /oe /we /cs1 cs2 /oe /we 128K x 8 128K x 8 D15 .. D8 High Byte D7 .. D0 Low Byte
ADDRESS LATCHES MC9SDP256B12 ADDR7 - ADDR0 PB7 - PB0 CLK ADDR 15 - ADDR8 PA7 - PA0 CLK ECLK PE4 ADDRESS LATCHED BY ON CLK
DemultiplexedAddress ECLK ADR2 ADR3 ADR4 ADR1 DAT2 DAT3 DAT3 DAT1 Demultiplexed Address ADR1 ADR2 ADR3 ADR4
PAGE ADDRESSING FOR EMULATION EXPANDED MODES MC9SDP256B12 PK5 - PK0 XADDR19 - XADDR 14 PK7 ECS (IF ECS = 0, USE XADDR19 - XADDR 14, ALONG WITH ADDR13 - ADDR0) (IF ECS = 1, USE ONLY ADDR15 - ADDR0)
GENERATION OF READ AND WRITE SIGNALS FOR MEMORY INTERFACING ECLK WE R/W (WRITE) OE (READ)
In the Normal Expanded Narrow Mode and the Normal Expanded Wide Mode, the Page Window Access Memory Region Can be Allocated Between External Memory and Internal Memory
The ECS Signal is activated in the Emulation Expanded Narrow Mode and the Emulation Expanded Wide Mode when the Microcontroller Tries to Access Memory Through the Page Access Window Which Would Have Been Accessed Internally if the Normal Expanded Narrow Mode or the Normal Expanded Wide Mode, Respectively, Had Been Used.