PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 57

• Manufacturer Part Number: PSB7238
• Description: Joint Audio Decoder-Encoder - Multimode
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

PSB 7238
Functional Blocks
Caption to the Figure
The data from the shift register is loaded into DSP accessible receive read registers
(HRR1/2) and simultaneously into (physically separate) host accessible receive read
registers. Data to the HDLC receiver is loaded from the receive write register (HRW1/2)
accessible from the DSP (if HHR = 0) or the register accessible from the host
(if HHR = 1). Two separate control bits HHR1 and HHR2 are provided for this purpose,
for HDLC channel 1 and channel 2, respectively.
Figure 24
Caption to the Figure
The data from the HDLC transmitter is loaded into DSP accessible transmit read
registers (HXR1/2) and simultaneously into (physically separate) host accessible read
registers. Data is loaded into the shift register from the transmit write register (HXW1/2)
accessible from the DSP (if HHX = 0) or the register accessible from the host
(if HHX = 1). Two separate control bits HHX1 and HHX2 are provided for this purpose,
for HDLC channel 1 and channel 2, respectively.
The access right to the receiver and transmitter write registers (HRW1/2, HXW1/2) from
the DSP or the host (determined bits HHR1,2 and HHX1,2) is independent of who is
allowed to service the HDLC controller (determined by bits HAH1,2).
Semiconductor Group
57
Data Sheet 1998-07-01