Page 27

KM416RD8AS

Rev. 0.9 July 1999

Target

Control Register Packets

Table 14 summarizes the formats of the four packet types for

control register transactions. Table 15 summarizes the fields

that are used within the packets.

Figure 25 shows the transaction format for the SETR,

CLRR, and SETF commands. These transactions consist of a

single SRQ packet, rather than four packets like the SWR

and SRD commands. The same framing sequence on the

CMD input is used, however. These commands are used

during initialization prior to any control register read or

write transactions.

Figure 25: SETR, CLRR,SETF Transaction

SCK

CMD

SIO0

SRQ packet - SETR/CLRR/SETF

1111

00000000...00000000

SRQ packet - SETR/CLRR/SETF

0000

SIO1

The packet is repeated

from SIO0 to SIO1

1

1

1

1

0

0

0

0

Table 14: Control Register Packet Formats

SCK

Cycle

SIO0 or

SIO1

for SRQ

SIO0 or

SIO1

for SA

SIO0 or

SIO1

for SINT

SIO0 or

SIO1

for SD

SCK

Cycle

SIO0 or

SIO1

for SRQ

SIO0 or

SIO1

for SA

SIO0 or

SIO1

for SINT

SIO0 or

SIO1

for SD

0

rsrv

rsrv

0

SD15

8

SOP1

SA7

0

SD7

1

rsrv

rsrv

0

SD14

9

SOP0

SA6

0

SD6

2

rsrv

rsrv

0

SD13

10

SBC

SA5

0

SD5

3

rsrv

rsrv

0

SD12

11

SDEV4

SA4

0

SD4

4

rsrv

SA11

0

SD11

12

SDEV3

SA3

0

SD3

5

SDEV5

SA10

0

SD10

13

SDEV2

SA2

0

SD2

6

SOP3

SA9

0

SD9

14

SDEV1

SA1

0

SD1

7

SOP2

SA8

0

SD8

15

SDEV0

SA0

0

SD0

Table 15: Field Description for Control Register Packets

Field

Description

rsrv

Reserved. Should be driven as “0” by controller.

SOP3..SOP0

0000 - SRD. Serial read of control register {SA11..SA0} of RDRAM {SDEV5..SDEV0}.

0001 - SWR. Serial write of control register {SA11..SA0} of RDRAM {SDEV5..SDEV0}.

1111 - NOP. No serial operation.

0011, 0101-1010, 1100-1110 - RSRV. Reserved encodings.

SDEV5..SDEV0

Serial device. Compared to SDEVID5..SDEVID0 field of INIT control register field to select the RDRAM to which the transac-

tion is directed.

SBC

Serial broadcast. When set, RDRAMs ignore {SDEV5..SDEV0} for RDRAM selection.

SA11..SA0

Serial address. Selects which control register of the selected RDRAM is read or written.

SD15..SD0

Serial data. The 16 bits of data written to or read from the selected control register of the selected RDRAM.

a. The SETR and CLRR commands must always be applied in two successive transactions to RDRAMs; i.e. they may not be used in isolation. This is called “SETR/CLRR Reset”.