Rainbow-electronics ATmega8HVD Manuel d'utilisateur télécharger pdf (Page 110)

110

8052B–AVR–09/08

ATmega4HVD/8HVD

20.8.3 BPSCTR – Battery Protection Short-current Timing Register

• Bit 7 – Res: Reserved Bits

This bit is reserved and will always read as zero.

• Bit 6:0 – SCPT6:0: Short-current Protection Timing

These bits control the delay of the Short-circuit Protection. The Short-circuit Timing can be set

with a step size of 62.5 µs as shown in Table 20-2 on page 110.

Notes: 1. The actual value depends on the actual frequency of the ”Ultra Low Power RC Oscillator” on

page 24. See ”Electrical Characteristics” on page 142.

2. Initial value: SCPT[0x10](1ms).

3. An additional delay up to T

can be expected after enabling the Discharge FET due to initial-

ization of the protection circuit. With nomial ULP frequency this delay is maximum 55 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.

20.8.4 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 20-3 on page 111.

Bit 76543210

– SCPT[6:0] BPSCTR

Read/Write R R/W R/W R/W R/W R/W R/W R/W

Initial Value 0 0 0 1 0 0 0 0

Table 20-2. Short-circuit Protection Reaction Time. SCPT[6:0] with corresponding Short-cir-

cuit Delay Time.

Short-circuit Protection Reaction Time

(1)

SCPT[6:0]

(2)

Typ

0x00 (23.0 - 86.0 µs) + T

(3)

0x01 (23.0 - 86.0 µs) + T

(3)

0x02 (85.5 - 148.5 µs) + T

(3)

0x03 (148.0 - 211.0 µs) + T

(3)

... ...

0x7E (7.84 - 7.90 ms) + T

(3)

0x7F (7.90 - 7.96 ms) + T

(3)

Bit 76543210

– – OCPT[5:0] BPOCTR

Read/Write R R R/W R/W R/W R/W R/W R/W

Initial Value 0 0 0 0 0 0 1 0

1 2 ... 105 106 107 108 109 110 111 112 113 114 115 ... 167 168

Commentaires sur ces manuels

Pas de commentaire

Rainbow-electronics ATmega8HVD Manuel d'utilisateur Page 110

Commentaires sur ces manuels

Produits connexes et manuels pour Capteurs Rainbow-electronics ATmega8HVD