Casio MZ-2000 - Manual (Page 16)

15
MZ-2000 MIDI Implementation
4.1.5 Parameter Set Bulk Dump
This section describes the bulk format for parameter set transfers.
How parameter sets are actually allocated depends on the MZ-2000 sound source specifications.
See sections 4.2 thorugh 4.11 for more information.
Unlike the data format for individual parameter changes, a memory image is sent in order to
increase the speed of the parameter set bulk dump. Pre- and post-processing required for each
parameter is performed after bulk dump of all the data is complete.
You can transfer multiple parameter sets during a session. When a single parameter set is very
large, it can be divided and transferred as multiple packets. In such a case, and address offset is
included as part of the data.
Transferring multiple small-size parameter sets using a single packet is not allowed. Each param-
eter set must always be transferred as a separate packet.
One-Way Communication Flow
A session starts with a BDR request by the data receiver or a BDS data send by the data sender.
The session ends after the data sender transfers the required amount of data for the number of
parameter sets.
When the MZ-2000 receives a BDR, it uses a BDS to return the corresponding parameter set.
When the MZ-2000 receives a BDS, it modifies the setting of the applicable parameter set.
Data is divided into packets of 256 bytes or less and transferred at fixed intervals (20 msec).
Data Receiver Data Sender
BDR -> Send Request (Optional)
<- BDS Data Transfer
Interval: 20 msec minimum
<- BDS Data Transfer
Interval: 20 msec minimum
<- BDS Data Transfer
Interval: 20 msec minimum
:
:
Hand Shake Protocol
A session starts with the data receiving sending an HDR request or an HDS data send from the
data sender.
The data sender does not send the next packet until it receives an acknowledgement (ACK) from
the data receiver. Be sure to reserve at least 100msec as the maximum wait time. If no response is
received within the prescribed time, a time out error occurs and communication is terminated.
If the data receiver returns an HDE (error) due to a checksum error, illegal data format, or any
other reason, the data sender resends the data. Resend the data at least one time.
The session ends after the data sender transfers the correct amount of data for the number of
parameter sets, and is terminated when an ACK is returned.
Data Receiver Data Sender
HDR -> Send Request(Optional)
<- HDS Data Send
HDA -> Acknowledge
<- HDS Data Send
HDA -> Acknowledge
:
:
Resend is performed after an error due to checksum error or data format error.
Data Receiver Data Sender
HDR -> Send Request (Optional)
<- HDS Data Send
HDA -> Acknowledge
<- HDS Data Send
HDE -> Acknowledge
<- HDS Data Resend
:
:
Send is terminated if there is no acknowledgement (ACK).
Data Receiver Data Sender
HDR -> Send Request (Optional)
<- HDS Data Send
HDA -> Acknowledge
<- HDS Data Send
(Send Terminated)
HDJ is sent whenever the session is terminated for any reason. HDJ can be sent from either the
sender or receiver. Receipt of HDJ immediately terminates a bulk dump.
Data Receiver Data Sender
HDR -> Send Request (Optional)
<- HDS Data Send
HDA -> Acknowledge
<- HDS Data Send
:
HDJ -> Data Receive Rejection
(Send Terminated)
Data Receiver Data Sender
HDR -> Send Request (Optional)
HDA -> Acknowledge
<- HDS Data Send
HDA -> Acknowledge
<- HDS Data Send
:
<- HDJ Data Send Rejection
Parameter Set HDJ/HDA/HDE
tt 0100aaaa aaaa = HDJ/HDA/HDE
No data in the case of Rejection, Acknowledge, or Error
Parameter Set BDS/HDS
tt 0100aaaa aaaa = BDS/HDS
d0[0] 0ooocccc cccc = Parameter Set Category
ooo = option (Definition for each category)
d0[1] 0ttttttt 0TTTTTTT0ttttttt = Type ID
d0[2] 0TTTTTTT
d0[3] 0mmmmmmm 0MMMMMMM0mmmmmmm = Mdev ID
d0[4] 0MMMMMMM
d0[5] 0sssssss 00SSSSSSSsssssss = Section Number
d0[6] 0SSSSSSS
d0[7] 0nnnnnnn 00NNNNNNNnnnnnnn = PS Number
d0[8] 0NNNNNNN