ZLF645S2864GP0001 Maxim Integrated, ZLF645S2864GP0001 Datasheet - Page 148

• Manufacturer Part Number: ZLF645S2864GP0001
• Description: 8-bit Microcontrollers - MCU Crimzon Flash Infrared MCU
• Manufacturer: Maxim Integrated

Specifications of ZLF645S2864GP0001

• Core: Z8
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 1 KB
• Operating Supply Voltage: 2 V to 3.6 V
• Interface Type: UART
• Number Of Programmable I/os: 5
• Number Of Timers: 2 x 8 bit, 1 x 16 bit
• Processor Series: ZLF645
• Program Memory Type: Flash

Table 67. Low-Voltage Detection Register (LVD)
19-4572; Rev 0; 4/09
Bit
Field
Reset
R/W
Address
Bit Position
[7:3]
[2] 
Voltage Detection
Note:
R
7
1
To enter HALT mode, first flush the instruction pipeline to avoid suspending execution in
mid-instruction. Execute a NOP instruction (OpCode =
appropriate sleep instruction, as given below:

FF
7F
Power consumption during HALT mode can be reduced by first setting SMR[0]=1 to
enable the divide-by-16 clock prescaler.
The Low-Voltage Detection register (LVD, register 0Ch at the expanded register bank
0Dh) provides an option to monitor the V
when bit 0 of LVD register is set. After voltage detection is enabled, the V
monitored in real time. The HVD flag (bit 2 of the LVD register) is set only if V
higher than V
than the V
The IRQ bit 5 latches the low voltage condition until it is cleared by instructions or reset.
The IRQ5 interrupt is served if it is enabled in the IMR register. Otherwise, bit 5 of IRQ
register is latched as a flag only.
Do not modify register P01M while checking a low voltage condition. Switching noise
from Port 0 can trigger the LVD flag.
Value
—
0
1
R
6
1
LVD
Description
Reserved—Reads 11111b. Must be written to 1.
HVD clear.
High-voltage detected (V
Reserved
HVD.
. When voltage detection is enabled, the LVD flag also triggers IRQ5. 
R
5
1
The LVD flag (bit 1 of the LVD register) is set only if V
NOP
HALT
R
4
1
Bank D: 0Ch; Linear: D0Ch
R
3
1
DD
; clear the pipeline
; enter HALT mode
>V
High-Battery
HVD)
DD
Detect
R
2
0
voltage. The voltage detection is enabled
Low-Battery
ZLF645 Series Flash MCUs
FFh
Detect
R
1
0
) immediately before the
Product Specification
Voltage Detection
Detect Enable
DD
Voltage
level is 
DD
R/W
0
0
is lower
DD
is
140