71M6403
Electronic Trip Unit
SEPTEMBER 2006
Page: 19 of 75
©
2006 TERIDIAN Semiconductor Corporation
REV 1.0
Port Registers:
The I/O ports are controlled by Special Function Registers
P0
,
P1
, and
P2
. The contents of the SFR can be
observed on corresponding pins on the chip. Writing a ‘1’ to any of the ports (see Table 9) causes the corresponding pin to be at
high level (V3P3), and writing a ‘0’ causes the corresponding pin to be held at low level (GND). The data direction registers
DIR0
,
DIR1
, and
DIR2
define individual pins as input or output pins (see the DIO section in On-Chip Resources for details.
Register
SFR
Address
R/W
Description
P0
0x80
R/W
Register for port 0 read and write operations (pins DIO0…DIO7)
DIR0
0xA2
R/W
Data direction register for port 0. Setting a bit to 1 means that the corresponding pin is
an output.
P1
0x90
R/W
Register for port 1 read and write operations (pins DIO8…DIO15)
DIR1
0x91
R/W
Data direction register for port 1.
P2
0xA0
R/W
Register for port 2 read and write operations (pins DIO16…DIO21)
DIR2
0xA1
R/W
Data direction register for port 2.
Table 9: Port Registers
All four ports on the chip are bi-directional. Each of them consists of a Latch (SFR ‘P0’ to ‘P3’), an output driver, and an input
buffer, therefore the MPU can output or read data through any of these ports if they are not used for alternate purposes.
Special Function Registers Specific to the 71M6403
Table 10 shows the location and description of the 71M6403-specific SFRs.
Register
Alternative
Name
SFR
Address
R/W Description
ERASE FLSH_ERASE
0x94 W
This register is used to initiate either the Flash Mass Erase cycle or the
Flash Page Erase cycle. Specific patterns are expected for
FLSH_ERASE
in order to initiate the appropriate Erase cycle (default =
0x00).
0x55 – Initiate Flash Page Erase cycle. Must be preceded by a write to
FLSH_PGADR
@ SFR 0xB7.
0xAA – Initiate Flash Mass Erase cycle. Must be preceded by a write to
FLSH_MEEN
@ SFR 0xB2 and the debug port must be
enabled.
Any other pattern written to FLSH_ERASE will have no effect.
PGADDR FLSH_PGADR
0xB7 R/W
Flash Page Erase Address register containing the flash memory page
address (page 0 thru 127) that will be erased during the Page Erase
cycle (default = 0x00).
Must be re-written for each new Page Erase cycle.
EEDATA
0x9E
R/W
I
2
C EEPROM interface data register
EECTRL
0x9F
R/W
I
2
C EEPROM interface control register. If the MPU wishes to write a byte
of data to EEPROM, it places the data in
EEDATA
and then writes the
‘Transmit’ code to
EECTRL
. The write to
EECTRL
initiates the transmit
sequence. See the section I2C Interface (EEPROM) for a description of
the command and status bits available for
EECTRL
.
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