MT92220BG Zarlink Semiconductor, MT92220BG Datasheet - Page 23

• Manufacturer Part Number: MT92220BG
• Description: Description = 1023 Channel Voice Over IP/AAL2 Processor ;; Package Type = Epbga ;; No. Of Pins = 608
• Manufacturer: Zarlink Semiconductor

Data Sheet
2.3.1
Extended Indirect Accessing solely employees the registers 000h to 00Ah to access the 128 Megabytes of
addressable memory space. The access address is written to registers 000h, 008h, and 00Ah. The MT92220 will
read/write to that address and fetch /place the data value from/to register 004h. For all extended indirect accesses
the cpu_a_das pin will be held low.
2.3.1.1 Extended Indirect Writes
1. Write the upper address, extended_a[32:20], to register 008h. This may not be required if previous value holds
2. Write the lower address, extended_a [19:4], to register 00Ah. This may not be required if previous value holds
3. Write the write data, extended_data[15,0], to register 004h.This may not be required if previous value holds
4. Write write_enable, extended_parity, access_req=’1’ and extended_a [3:1] in a single access to register
5. Read the access_req bit located in the Control Register[8] to determine when the write cycle has completed.
The software will set access_req[8] in register 000h. The hardware will reset the bit when the data write cycle has
completed. Therefore, this bit can be polled to determine when the data write cycle has completed.
2.3.1.2 Extended Indirect Reads
1. Write the upper address, extended_a[32:20], to register 008h.This may not be required if previous value holds
2. Write the lower address, extended_a [19:4], to register 00Ah. This may not be required if previous value holds
3. Write write_enable=”00”, access_req=’1’ and extended_a [3:1] in a single access to register 000h.
4. Wait until access_req is cleared, then read data from the data field extended_data[15,0], register 004h.
Optional parity check may be ascertained by performing a read on the extended_parity[15,14], register 000h. The
software will set access_req[8] in register 000h and then the hardware will reset it when the data is ready to be read
from register 004h.
extended_a[19:4]
true.
true.
true.
000h.
true.
true.
Field
Extended Indirect Access Procedures
15:0
Bit
RW
Type
Table 6 - Address Low Register (00Ah)
0000h
Reset
Zarlink Semiconductor Inc.
Extended address bits 19:4. extended_a[32:0] points to bytes.
Some bits in this register are not used in direct accesses. When
operating the CPU interface with a 16 bit data bus, only bits 19:16
are used. When operating the CPU interface with an 8-bit data
bus, only bits 19:15 are used.
Description
MT92220
23