Datasheet

129
8024A–AVR–04/08
ATmega8HVA/16HVA
Notes: 1. The actual value depends on the actual frequency of the ”Ultra Low Power RC Oscillator” on
page 26. See ”Electrical Characteristics” on page 165.
2. Initial value: SCPT[0x10](1ms).
3. An additional delay T
d
can be expected after enabling the Discharge FET due to initialization of
the protection circuit. With nomial ULP frequency this delay is maximum 86 µs.
Note: Due to synchronization of parameters between clock domains, a guard time of 3 ULP oscillator
cycles + 3 CPU clock cycles is required between each time the BPSCTR register is written. Any
writing to the BPSCTR register during this period will be ignored.
23.9.4 BPOCTR – Battery Protection Over-current Timing Register
• Bit 7:6 – Res: Reserved Bits
These bits are reserved and will always read as zero.
• Bit 5:0 – OCPT5:0: Over-current Protection Timing
These bits control the delay of the Over-circuit Protection. The Over-current Timing can be set
with a step size of 0.5 ms as shown in Table 23-3 on page 129.
Notes: 1. The actual value depends on the actual frequency of the ”Ultra Low Power RC Oscillator” on
page 26. See ”Electrical Characteristics” on page 165.
2. Initial value.
3. An additional delay T
d
can be expected after enabling the corresponding FET. This is related to
the initialization of the protection circuitry. For the Discharge Over-Current protection, this
... ...
0x7E (7.83 - 7.88 ms) + T
d
(3)
0x7F (7.89 - 7.95 ms) + T
d
(3)
Table 23-2. Short-circuit Protection Reaction Time. SCPT[6:0] with corresponding Short-cir-
cuit Delay Time.
Short-circuit Protection Reaction Time
(1)
Bit 76543210
(0xFB) – – OCPT[5:0] BPOCTR
Read/Write R R R/W R/W R/W R/W R/W R/W
Initial Value00000010
Table 23-3. Over-current Protection Reaction Time. OCPT[5:0] with corresponding Over-cur-
rent Delay Time.
Over-current Protection Reaction Time
(1)
OCPT[5:0] Typ
0x00 (0.0 - 0.5 ms) + T
d
(3)
0x01 (0.0 - 0.5 ms) + T
d
(3)
0x02
(2)
(0.5 - 1.0 ms) + T
d
(3)
0x03 (1.0 - 1.5 ms) + T
d
(3)
... ...
0x3E (30.5 - 31.0 ms) + T
d
(3)
0x3F (31.0 - 31.5 ms) + T
d
(3)