71M6531D Datasheet, PDF (26/115 Pages) Teridian Semiconductor Corporation – Energy Meter IC

Data Sheet 71M6531D/F-71M6532D/F
FDS 6531/6532 005
Register
(Alternate
Name)
IFLAGS
IFLAGS (cont.)
INTBITS
(INT0 … INT6)
SFR
Address
Bit Field
Name
R/W
Description
0xE8[0] IE_XFER
R/W This flag monitors the XFER_BUSY interrupt. It
is set by hardware and must be cleared by the
interrupt handler.
0xE8[1] IE_RTC
R/W This flag monitors the RTC_1SEC interrupt. It
is set by hardware and must be cleared by the
interrupt handler.
0xE8[2] FW_COL0
R/W This flag indicates that a flash write was at-
tempted while the CE was busy.
0xE8[3] FW_COL1
R/W This flag indicates that a flash write was in pro-
gress when the CE was attempting to begin a
code pass.
0xE8[4] IE_PB
R/W This flag indicates that the wake-up pushbutton
was pressed.
0xE8[5]
0xE8[6]
IE_WAKE
PLL_RISE
R/W This flag indicates that the MPU was awakened
by the autowake timer.
R/W PLL_RISE Interrupt Flag:
Write 0 to clear the PLL_RISE interrupt flag.
0xE8[7] PLL_FALL
R/W PLL_FALL Interrupt Flag:
Write 0 to clear the PLL_FALL interrupt flag.
0xF8[6:0] INT6 … INT0
R Interrupt inputs. The MPU may read these bits
to see the status of external interrupts INT0 up
to INT6. These bits do not have any memory
and are primarily intended for debug use.
0xF8[7] WD_RST
W The WDT is reset when a 1 is written to this bit.
Only byte operations on the entire INTBITS register should be used when
writing. The byte must have all bits set except the bits that are to be cleared.
1.4.5 Instruction Set
All instructions of the generic 8051 microcontroller are supported. A complete list of the instruction set
and of the associated op-codes is contained in the 71M653X Software User’s Guide (SUG).
1.4.6 UARTs
The 71M6531D/F and 71M6532D/F includes a UART (UART0) that can be programmed to communicate
with a variety of AMR modules. A second UART (UART1) is connected to the optical port, as described
in Section 1.5.6 Optical Interface.
The UARTs are dedicated 2-wire serial interfaces, which can communicate with an external host pro-
cessor at up to 38,400 bits/s (with MPU clock = 1.2288 MHz). The operation of the RX and TX UART0
pins is as follows:
• UART0 RX: Serial input data are applied at this pin. Conforming to RS-232 standard, the bytes are
input LSB first.
• UART0 TX: This pin is used to output the serial data. The bytes are output LSB first.
The 71M6531D/F and 71M6532D/F have several UART-related registers for the control and buffering of
serial data.
The serial buffers consist of sets of two separate registers (one set for each UART), a transmit buffer
(S0BUF, S1BUF) and a receive buffer (R0BUF, R1BUF). Writing data to the transmit buffer starts the
transmission by the associated UART. Received data are available by reading from the receive buffer.
Both UARTs can simultaneously transmit and receive data.
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