MCP8021 datasheet(32/66 Pages) MICROCHIP

32 / 66 page

MCP8021/2

DS20006265D-page 32

 2020-2024 Microchip Technology Inc. and its subsidiaries

The PCON bits of the STAT0 register will be set every

time the device restarts due to various events (see

Table 4-3). When the driver resumes operation, a single

unsolicited STATUS_0 message will be sent to the host

indicating a Reset has occurred. The message will be

sent five milliseconds (5 ms) after the VREG LDO has

reached its active state. The host should check the

PCON bits to determine the cause of the power cycle.

In all cases, the configuration data may have been lost

and should be re-sent to the driver. The PCON flags are

reset by a host STATUS_0 request message. If the host

misses the unsolicited STATUS_0 message at start-up,

the host may manually request the status by sending a

STATUS_0 message to the driver. The PCON bits of the

STAT0 register will contain the source of the Power-on

Reset until the STAT0 register is requested by the host.

4.8.7.4

SET_CFG_2

There is a SET_CFG_2 message that is sent by the host

to the MCP8021/2 devices to configure the driver current

limit blanking time. The SET_CFG_2 message may be

sent to the devices at any time. The host is responsible

for making sure the system is in a state that will not be

compromised by sending the SET_CFG_2 message.

The SET_CFG_2 message format is indicated in

Table 4-6. The response is indicated in Table 4-7.

4.8.7.5

GET_CFG_2

There is a GET_CFG_2 message that is sent by the

host to the MCP8021/2 devices to retrieve the device

Configuration Register #2. The GET_CFG_2 message

format is indicated in Table 4-6. The response is

indicated in Table 4-7.

FIGURE 4-4:

DE2 Packet Format.

FIGURE 4-5:

DE2 Packet Timing.

STOP

START

DE2

Message Format

T = 1/Baud Rate (bit cell period)

Detect Start Bit by Sensing

Transition from Logic ‘1’ to Logic ‘0’

TS = T/16 (oversampled bit cell period)

Receiver Samples the Incoming Data

Using x16 Baud Rate Clock

TSTART = 1.5T – Uncertainty on Start

Detection (worst-case: 2x TS)

Sample Incoming Data

at the Bit Cell Center

START

TSTART

STOP

MCP8021 数据表(PDF) 32 Page - Microchip Technology

MCP8021 数据表(HTML) 32 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

数据表下载