em78p510nso32j/s ELAN Microelectronics Corp, em78p510nso32j/s Datasheet - Page 43

• Manufacturer Part Number: em78p510nso32j/s
• Description: 8-bit Microprocessor With Otp Rom
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.1) 01.25.2008
(This specification is subject to change without further notice)
1
Note: VDD=5V, Setup time period = 16.5ms ± 30% VDD=3V, Setup time period = 18ms ± 30%
Setup time form the WDT.
6.3 TCC/WDT Prescaler
Registers for the TCC/WDT Circuit
There are two 8-bit counters available as prescales for the TCC and WDT, respectively.
The TPSR0~TPSR2 bits of the Bank 0 RD (TWTCR) register are used to determine the
ratio of the TCC prescale. Likewise, the WPSR0~WPSR2 bits of the Bank 0 RD
(TWTCR) register are used to determine the WDT prescale. The prescale
(TPSR0~TPSR2) will be cleared by the instructions each time they are written into TCC.
The WDT and prescale will be cleared by the “WDTC” and “SLEP” instructions. Figure
6-4 depicts the circuit diagram of TCC/WDT.
R1 (TCC) is an 8-bit timer/counter. The TCC clock source can be internal clock main
clock or sub clock (32.768kHz). If TCC signal source is from the internal clock, TCC will
be incremented by 1 at every instruction cycle (without prescale). As illustrated in
Figure 6-4. The watchdog timer is a free running on-chip RC oscillator. The WDT will
continue running even after the oscillator driver has been turned off (i.e. in sleep mode).
During normal operation or sleep mode, a WDT time-out (if enabled) will cause the
device to reset. The WDT can be enabled or disabled at any time during the normal
mode by software programming. Refer to WDTE bit of Bank 0 RD (TWTCR) register.
With no prescale, the WDT time-out period is approximately 18 ms
R_BANK Address NAME
Bank 0
Bank 0
Bank 0
0X0D
0x0E
0x0F
TWTCR WDTE WPSR2 WPSR1 WPSR0 TCCS
IMR
ISR
Bit 7
T1IE
T1IF
R/W
R/W
R/W
LVDIE
LVDIF
Bit 6
R/W
R/W
R/W
ADIE
Bit 5
ADIF
R/W
R/W
R/W
8-Bit Microprocessor with OTP ROM
SPIIE URTIE EXIE9 EXIE8
SPIIF URTIF EXIF9 EXIF8
Bit 4
R/W
R/W
R/W
Bit 3
R/W
R/W
R/W
TPSR2 TPSR1 TPSR0
Bit 2
R/W
R/W
R/W
1
.
EM78P510N
Bit 1
R/W
R/W
R/W
TCIE
TCIF
Bit 0
R/W
R/W
R/W
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