Datasheet

71M6511/71M6511H

Single-Phase Energy Meter IC

DATA SHEET

NOVEMBER 2010

A Maxim Integrated Products Brand

Bit

Symbol

Function

TMOD.7

TMOD.3

Gate If set, enables external gate control (pin int0 or int1 for Counter 0 or 1,

respectively). When int0 or int1 is high, and TRX bit is set (see TCON register), a

counter is incremented every falling edge on t0 or t1 input pin

TMOD.6

TMOD.2

C/T Selects Timer or Counter operation. When set to 1, a Counter operation is

performed. When cleared to 0, the corresponding register will function as a Timer.

TMOD.5

TMOD.1

M1 Selects the mode for Timer/Counter 0 or Timer/Counter 1, as shown in TMOD

description.

TMOD.4

TMOD.0

M0 Selects the mode for Timer/Counter 0 or Timer/Counter 1, as shown in TMOD

description.

Table 20: TMOD Register Bit Description

M1 M0

Mode Function

0 0 Mode 0 13-bit Counter/Timer with 5 lower bits in the TL0 or TL1 register and the

remaining 8 bits in the TH0 or TH1 register (for Timer 0 and Timer 1,

respectively). The 3 high order bits of TL0 and TL1 are held at zero.

0 1 Mode 1 16-bit Counter/Timer.

1 0 Mode2 8-bit auto-reload Counter/Timer. The reload value is kept in TH0 or TH1,

while TL0 or TL1 is incremented every machine cycle. When TL

(x) overflows,

a value from TH(x) is copied to TL(x).

1 1 Mode3 If Timer 1 M1 and M0 bits are set to '1', Timer 1 stops. If Timer 0 M1 and M0

bits are set to '1', Timer 0 acts as two independent 8-bit Timer/Counters.

Table 21: Timers/Counters Mode Description

Note: TL0 is affected by TR0 and gate control bits, and sets TF0 flag on overflow.