MEC1322 datasheet(361/456 Pages) MICROCHIP

361 / 456 page

 2014 - 2015 Microchip Technology Inc.

DS00001719D-page 361

MEC1322

The Master state machine loads the Data Register, issues a BUSY Bit Clear interrupt and clears the BUSY bit to

‘0’.

Software, after either receiving the Bit Clear interrupt, or polling the BUSY bit until it is ‘0’, checks the BC_ERR

bit in the Status Register.

Software can now read the Data Register which contains the valid data if there was no BC Bus error.

If a Bus Error occurs, firmware must issue a soft reset by setting the RESET bit in the Status Register to ‘1’.

The read can re-tried once BUSY is cleared.

31.10.2

BC-LINK MASTER WRITE OPERATION

Software starts by checking the status of the BUSY bit in the BC-Link Status Register. If the BUSY bit is ‘0’, pro-

ceed. If BUSY is ‘1’, firmware must wait until it is ‘0’.

Software writes the address of the register to be written into the BC-Link Address Register.

Software writes the data to be written into the addressed register in to the BC-Link Data Register.

The write to the Data Register starts the BC_Link write operation. The Master state machine sets the BUSY bit.

The BC-Link Master Interface transmits the write request packet.

When the write request packet is received by the BC-Link companion, the CRC is checked and data is written to

the addressed companion register.

The companion sends an ACK if the write is completed. A time-out will occur approximately 16 BC-Link clocks

after the packet is sent by the Master state machine. If a time-out occurs, the state machine will set the BC_ERR

bit in the Status Register to ‘1’ approximately 48 clocks later and then clear the BUSY bit.

The Master state machine issues the Bit Clear interrupt and clears the BUSY bit after receiving the ACK from the

Companion

If a Bus Error occurs, firmware must issue a soft reset by setting the RESET bit in the Status Register to ‘1’.

10. The write can re-tried once BUSY is cleared.

31.11 EC-Only Registers

The registers listed in the EC-Only Register Summary table are for a single instance of the BC-Link Master interface.

The addresses of each register listed in this table are defined as a relative offset to the host “Base Address” defined in

the EC-Only Register Base Address Table.

Note 31-1

The Base Address indicates where the first register can be accessed in a particular address space

for a block instance.

Note:

Steps 3 thorough 7 should be completed as a contiguous sequence. If not the interface could be presenting

incorrect data when software thinks it is accessing a valid register read.

TABLE 31-7:

EC-ONLY REGISTER BASE ADDRESS TABLE

Block Instance

Instance

Number

Host

Address Space

Base Address (

Note 31-1)

BC-LINK

32-bit internal

address space

4000_BC00h

TABLE 31-8:

EC-ONLY REGISTER SUMMARY

EC Offset

BC-Link Status Register

00h

BC-Link Address Register

04h

BC-Link Data Register

08h

BC-Link Clock Select Register

0Ch

MEC1322 Datasheet(PDF) 361 Page - Microchip Technology

MEC1322 Datasheet(HTML) 361 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 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL