PEB20571 INFINEON [Infineon Technologies AG], PEB20571 Datasheet - Page 126

• Manufacturer Part Number: PEB20571
• Description: ICs for Communications
• Manufacturer: INFINEON [Infineon Technologies AG]

Preliminary Data Sheet
4.9
4.9.1
The µP and the DSP communicate via a bidirectional Mailbox according to the mailbox
protocol described in Chapter 11. The DELIC provides two dedicated Mailboxes that
may be used in two operational modes:
• DMA mode in which the two Mailboxes operate independently, one serves as a
• Expanded Mailbox mode in which the two Mailboxes are regarded as a enlarged
The general purpose Mailbox includes two separate parts:
• µP Mailbox - enables transfers from the µP to the OAK.
• OAK DSP Mailbox - enables transfers from the OAK to the µP.
Both parts include a command register, 9 x (16-bit) registers (17 registers in expanded
mode) and a busy bit. One of the data registers in every part has a special addressing
mode, i.e. the OAK may access either a certain byte of a word or the whole word which
is temporarily stored in the Mailbox. This requires to use 3 different addresses in OAK’s
direction.
Note: The Mailbox protocol commands structure is described in Chapter 11.
4.9.2
The µP Mailbox includes:
• Eight 16-bit data registers (MDTn)
• A16-bit general register (MGEN)
• An 8-bit command register (MCMD)
• A 1-bit busy register (MBUSY)
Registers MDTn, MGEN and MCMD may be written by the µP and read by the OAK. The
MBUSY register may be written by the DSP and read by the µP.
A write of the µP to the MCMD-register of the µP-mailbox generates an interrupt to the
OAK. Thus, the user has to provide all mailbox data prior to writing to register MCMD.
The MBUSY bit which may be read by the µP (register MBUSY) is set automatically after
a write to the µP command register (MCMD) and reset automatically by a direct OAK
write operation to it.
Note: The command Opcodes are defined in Chapter 11.
Data Transfer from the µP to the OAK
• The µP reads the busy bit and checks whether the Mailbox is available (MBUSY=’0’)
general purpose Mailbox and the other serves as a DMA Mailbox.
general purpose Mailbox, providing a double number of registers.
General Mailbox
Overview
µP Mailbox
4-42
Functional Description
DELIC
2003-08