Datasheet

71M6511/71M6511H
Single-Phase Energy Meter IC
DATA SHEET
NOVEMBER 2010
Page: 20 of 98 © 2005–2010 Teridian Semiconductor Corporation V2.7
A Maxim Integrated Products Brand
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 11) 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 section On-Chip Resources – DIO Ports for
details).
Register SFR
Addres
s
R/W Description
P0 0x80 R/W Register for port 0 read and write operations (pins DIO4…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-DIO17)
DIR2 0xA1 R/W Data direction register for port 2.
Table 11: 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. Even if a DIO pin is configured as an output, the
state of the pin can still be read by the MPU, for example when counting pulses issued via DIO pins that are under CE control.
Special Function Registers Specific to the 71M6511
Table 12 shows the location and description of the 71M6511-specific SFRs.
Register Alternative
Name
SFR
Addres
s
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 proceeded by a write
to FLSH_PGADR @ SFR 0xB7.
0xAA – Initiate Flash Mass Erase cycle. Must be proceeded 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 I2C EEPROM interface data register
EECTRL 0x9F R/W I2C 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.